EDataBookFactory: Always watch sender's bus name.
EDataBookFactory: Always watch sender's bus name.

Watch the sender's bus name on every new connection so we can clean up
its connections if the bus name vanishes (e.g. client program crashes).

Previously we were only watching the sender's bus name if the backend
instance was created for that connection, but that was unintentional.

Distrotech/evolution-data-server,tintou/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,matzipan/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server