Fix deadlock in SF.

problem was that we were acquiring a strong reference
on Connection object with a lock held, when those
got out of scope (lock still held) their dtor
could be called if all other refs had dropped,
the dtor would acquire the lock again to
remove the Connection from the main list. boom.

we rearange the code so this doesn't happen.

Bug: 6942208

Change-Id: I0a0ebabce2842d29d60d645b64aac2f26640e59b