pairing BT speaker when on going call causes a never ending call

Enviroment:

current build number: 818
device name: krillin
channel: ubuntu-touch/rc-proposed/bq-aquaris.en-proposed
last update: 2016-08-25 15:25:54
version version: 818
version ubuntu: 20160825
version device: 20160606-ab415b2
version custom: 20160824-991-38-17

Product: BQ E4.5 FHD
Preconditions:

- Pair a BT speaker and set it to autoconnect
- Start the test case with BT switched off on the phone and the BT speaker ready to connect

Steps to reproduce:

1º Receive a phone call
2º Press back button on dialer app, enter your password and check the dialer dialog in upper edge with call's duration.
2º Turn on BT and check that it connects automatically
3º Close dialer app and try to reopen it, the dialpad will appear instead of the live call on going
4º Finish the call from remote side and check the that upper bar on the phone still counts call time and there is no way to hung up

Current result: Cannot hung up once a BT speaker was connected during a call

Expected result: Dialer app should show the live call screen and let the user hung up

Add info: If you connect the BT speaker when receiving the call, instead of being established unity8 could crash and the loading screen will appear(happened 2 times). Logs attached time stamp 19:30