[#3134] Fix pulseaudio volume jumps to 100% at startup

Just needed to pass NULL as an argument for volume when opening streams

sflphone-common/src/audio/pulseaudio/audiostream.cpp

@@ -198,7 +198,7 @@ AudioStream::createStream (pa_context* c)
         attributes->minreq = (uint32_t) -1;
 
 		pa_threaded_mainloop_lock(_mainloop);
-        pa_stream_connect_playback (s , NULL , attributes, (pa_stream_flags_t)(PA_STREAM_ADJUST_LATENCY|PA_STREAM_AUTO_TIMING_UPDATE), &_volume, NULL);
+        pa_stream_connect_playback (s , NULL , attributes, (pa_stream_flags_t)(PA_STREAM_ADJUST_LATENCY|PA_STREAM_AUTO_TIMING_UPDATE), NULL, NULL);
 		pa_threaded_mainloop_unlock(_mainloop);
 
     } else if (_streamType == CAPTURE_STREAM) {