Bluetooth: L2CAP: Clear channel options if configure fails

On every configuration request clean options before setting anything.
Then if configuration will be rejected options will not be set to
something that is not set in next configure request.

Change-Id: I5acedde96f7ff720e916256d683937acbcd13a48
Reviewed-on: https://code.wireshark.org/review/3765
Reviewed-by: Michal Labedzki <michal.labedzki@tieto.com>