EXT-8065 FIXED added hiding Start IM button on a group call invitation dialog
EXT-8065 FIXED added hiding Start IM button on a group call invitation dialog

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/675/

gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm