Stuck in Searching/Connecting: Resolve the two requests mystery

Related to https://git.jami.net/savoirfairelinux/ring-daemon/issues/227

Reproduce steps

1. device B cut its connectivity
2. device A calls device B (with the connecting lock, cf https://git.jami.net/savoirfairelinux/ring-daemon/issues/243)
3. device A is blocked in "Searching"
4. after a while, device B is back online
5. device A receives 2 ICE response

Expected results

Only one answer should be received (the one from the fallback request)

changed milestone to %Iteration 19

mentioned in issue #227 (closed)

added SprintIn progress label

Some logs. Seems there is 2 fallbacks

[1593200259.107| 4226|call.cpp          :104  ] Call 4832579769172963 is still connecting after timeout, sending fallback request
[1593200259.108| 4226|call.cpp          :104  ] Call 1929774272225073 is still connecting after timeout, sending fallback request
[1593200259.108| 4226|jamiaccount.cpp   :486  ] [call 1929774272225073] calling device 82a49fdf28dbafc85b43f50235e9b36e1efa52a8
[1593200259.108| 4226|ringbufferpool.cpp:118  ] Ringbuffer created with id '169222124490144'
[1593200259.108| 4226|ice_transport.cpp :217  ] [ice] added host stun server
[1593200259.108| 4226|ice_transport.cpp :217  ] [ice] added host stun server
[1593200259.108| 4226|ice_transport.cpp :278  ] [ice] added turn server '158.69.203.51', port 3478
[1593200259.108| 4226|ice_transport.cpp :278  ] [ice] added turn server '158.69.203.51', port 3478
[New Thread 0x7fff43fff700 (LWP 1447014)]
[1593200259.111| 4226|ice_transport.cpp :217  ] [ice] added host stun server
[1593200259.111| 4226|ice_transport.cpp :217  ] [ice] added host stun server
[1593200259.111| 4226|ice_transport.cpp :278  ] [ice] added turn server '158.69.203.51', port 3478
[1593200259.111| 4226|ice_transport.cpp :278  ] [ice] added turn server '158.69.203.51', port 3478
[1593200259.111| 5222|sip_utils.cpp     :203  ] Registered thread 0x7fff43ffe168 (0x16107E)
[New Thread 0x7fff437fe700 (LWP 1447015)]
[1593200259.113| 5223|sip_utils.cpp     :203  ] Registered thread 0x7fff437fd168 (0x16107E)
[1593200259.113| 4226|call.cpp          :435  ] [call:1929774272225073] add subcall 169222124490144
[1593200259.115| 5222|ice_transport.cpp :525  ] [ice:0x7fff84444000] UDP initialization success
[1593200259.115| 5222|ice_transport.cpp :578  ] ICE as master
[1593200259.116| 5222|ice_transport.cpp :672  ] [ice:0x7fff84444000] (local) ufrag=6478501c, pwd=3058cb835e5bff2e0b16d916

[1593200259.123| 5223|ice_transport.cpp :525  ] [ice:0x7fff8435a040] TCP initialization success
[1593200259.123| 5223|ice_transport.cpp :578  ] ICE as master
[1593200259.123| 5223|ice_transport.cpp :672  ] [ice:0x7fff8435a040] (local) ufrag=633850ee, pwd=2ecd87073381d17029feaf0f
[1593200259.126| 4226|call.cpp          :104  ] Call 4832579769172963 is still connecting after timeout, sending fallback request
[1593200259.126| 4226|call.cpp          :104  ] Call 1929774272225073 is still connecting after timeout, sending fallback request
[1593200259.126| 4226|jamiaccount.cpp   :486  ] [call 1929774272225073] calling device 82a49fdf28dbafc85b43f50235e9b36e1efa52a8
[1593200259.127| 4226|ringbufferpool.cpp:118  ] Ringbuffer created with id '5546683668603815'
[1593200259.127| 4226|ice_transport.cpp :217  ] [ice] added host stun server
[1593200259.127| 4226|ice_transport.cpp :217  ] [ice] added host stun server
[1593200259.127| 4226|ice_transport.cpp :278  ] [ice] added turn server '158.69.203.51', port 3478
[1593200259.127| 4226|ice_transport.cpp :278  ] [ice] added turn server '158.69.203.51', port 3478
[New Thread 0x7fff41ffb700 (LWP 1447016)]
[1593200259.129| 5224|sip_utils.cpp     :203  ] Registered thread 0x7fff41ffa168 (0x16107E)
[1593200259.130| 4226|ice_transport.cpp :217  ] [ice] added host stun server
[1593200259.130| 4226|ice_transport.cpp :217  ] [ice] added host stun server
[1593200259.130| 4226|ice_transport.cpp :278  ] [ice] added turn server '158.69.203.51', port 3478
[1593200259.130| 4226|ice_transport.cpp :278  ] [ice] added turn server '158.69.203.51', port 3478
[New Thread 0x7fff417fa700 (LWP 1447017)]
[1593200259.132| 5225|sip_utils.cpp     :203  ] Registered thread 0x7fff417f9168 (0x16107E)
[1593200259.132| 4226|call.cpp          :435  ] [call:1929774272225073] add subcall 5546683668603815
[1593200259.135| 5224|ice_transport.cpp :525  ] [ice:0x7fff845c8dc0] UDP initialization success

added SprintTo review label and removed SprintIn progress label

mentioned in commit 3a72e386

closed

removed SprintTo review label