WebRtcEndpointImpl: fix config loading

BUG=3922

Change-Id: I65943c40664c72cd1245d6f104ff24e5ab10785f
Ignore .idea files

Change-Id: Ifa939e4a153f90562e33b4243768727c8716bdf2
WebRtcEndpointImpl: Change default stun address and port

Change-Id: I524c90688cab86d1ac87b718739b6332678e94dd