mainmixer: Connect ports when main is changed
mainmixer: Connect ports when main is changed

Change-Id: Ib5981e246642eb1b2a8474307c2c297d206b9a2f

shelsonjava/kms-elements,Kurento/kms-elements,Kurento/kms-elements,TribeMedia/kms-elements,shelsonjava/kms-elements,Kurento/kms-elements,TribeMedia/kms-elements,TribeMedia/kms-elements,shelsonjava/kms-elements