fix audio loop being restarted when call is on hold

This caused an "infinite loop" for audio media resulting
in CPU being overcharged for nothing

This fix the problem on MacOS and on GNU/Linux when using PulseAudio
There is still a similar problem with Alsa.

Change-Id: I70e111c59125143d60b657898b04a0b65a638bd6
Tuleap: #576

src/sip/sipcall.cpp

@@ -842,12 +842,17 @@ SIPCall::startAllMedia()
 #endif
 
         rtp->updateMedia(remote, local);
-        if (isIceRunning()) {
-            rtp->start(newIceSocket(ice_comp_id + 0),
-                       newIceSocket(ice_comp_id + 1));
-            ice_comp_id += 2;
-        } else
-            rtp->start();
+
+        // Not restarting media loop on hold as it's a huge waste of CPU ressources
+        // because of the audio loop
+        if (getState() != CallState::HOLD) {
+            if (isIceRunning()) {
+                rtp->start(newIceSocket(ice_comp_id + 0),
+                           newIceSocket(ice_comp_id + 1));
+                ice_comp_id += 2;
+            } else
+                rtp->start();
+        }
 
         switch (local.type) {
 #ifdef RING_VIDEO