No call UI and alert on incoming SIP call.

[jonas-koeritz]

When receiving a call via a SIP account no indication what so ever is visible or audible. When tapping the Phone icon to open the phone app it provides you with a button to go to the active call but no call UI will become visible. Outgoing calls are working (call UI too) but selecting the type of call to make (when "Ask for every call" is set) won't happen and the call will be placed via mobile, outgoing calls via SIP only work when the "Internet Telephone number" field of a contact is used to initiate the call. I would like to participate in resolving this issue, I may provide logs and screenshot at will.