Prevent ManagedConnection from failing if a logging invocation yields (!...

...).

Q: But how can the logging invocation yield?!
A: Because you are logging to the syslog; /dev/log is a socket, and if
   the socket would normally block, a monkey-patched socket will yield.

Q: What was the consequence of this?
A: If you successfully subscribed before the line that restores subs,
   you would then try to subscribe again, causing STOMP to kick you off
   your connection and ruining the whole enterprise.  If you've seen
   errors with the phrase "allready exists" [sic], this might be why.