fix couldn't play moh when execute uuid_hold on bleg

[eighty-zou]

fix issue #1476

[briankwest]

Can you outline the use case because uuid_hold is as if FreeSWITCH itself pressed the hold, FS isn't involved in playing any hold music when you call it. It's use case is for an IVR needing to put something on hold:

Example:

PHONE -> FS1 -> FS2, FS can uuid_hold directed at FS1 and FS1 will play music to PHONE.

I just want to make sure you understand what this feature was for and it has little use in many cases, unless you're using FreeSWITCH as a phone itself.

[eighty-zou]

Can you outline the use case because uuid_hold is as if FreeSWITCH itself pressed the hold, FS isn't involved in playing any hold music when you call it. It's use case is for an IVR needing to put something on hold:

our use case:
In our callcenter we use browser which support webrtc as a phone. Our webrtc phone don't have hold function(In other words we dont't send any sip messages to freeswitch when agent click hold button on webrtc phone,but just send a request to freeswitch which will call uuid_hold on this channel) .

first : pstn->freeswitch->webrtc phone
second : click hold button on webrtc phone
third :call uuid_hold on the channel which associate webrtc phone

in freeswitch version 1.10.6 and before we can hear hold music but in version1.10.8 we can't.

[gpavinteractiv]

@briankwest
I have also posted our use case related to this regression in #1476
Please advise.

[cqlmq]

uuid_hold [outbound's uuid] , other channel couldn't play moh

[nathanleyton]

We have also just faced this bug with uuid_hold, similar use case to the other cases mentioned above. We need to perform the hold by api not sip. We are looking at a workaround using uuid displace but it would be good to see this fix in a future release. Thanks :-)