JingleCallStack: Update Jitsi dependency to ~> 2.8.1 and use iOS 11.0 as deployment target.
JingleCallStack: Update Jitsi dependency to ~> 2.8.1 and use iOS 11.0 as deployment target.

matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk