fix client startup problems

I cannot detect a consistent pattern to reproduce. smells like race condition.

this message repeats many times:

2012-10-06 02:55:03,452 - leap.eip.eipconnection - DEBUG - no state 2012-10-06 02:55:03,695 - leap.eip.openvpnconnection - WARNING - missing management socket

One theory is that it occurs (some times!) when previous session has been interrupted in an anormal way.

(from redmine: created on 2012-10-05, closed on 2012-10-14, duplicates #729 (closed))