multistream: be able to negotiate more than 2 media streams

Current pjproject's configuration only allow the daemon to negotiate
two medias streams. Which is not enough for multistream.
Modify this limit to 32 streams (2**5) and avoid any potential
crash if the remote tries to negotiate more streams.
Also, fix some loops.

Note: This may not be the best solution for what we want to achieve.
Another approach may be to use a video mixer, mixing all the
medias we want and always negotiate 2 media streams. However, this
patch will not block the other approach and fix some loops.

jami-project#1429

Change-Id: I71ff3088bbf5908945656d02872755226f452fc5