ipwrapper: event monitor: wait after kill

proc.kill() function alone leaves zombies, so i added
proc.wait() after it.

Change-Id: I6e7ed0a0dea368206b7ee94482251ae5e4fa7259
Signed-off-by: Petr Horáček <phoracek@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/31854
Reviewed-by: Dan Kenigsberg <danken@redhat.com>