BUG/MINOR: peers: init bind_proc to 1 if it wasn't initialized

BUG/MINOR: peers: init bind_proc to 1 if it wasn't initialized

Tim reported that in master-worker mode, if a stick-table is declared
but not used in the configuration, its associated peers listener won't
bind.

This problem is due the fact that the master-worker and the daemon mode,
depend on the bind_proc field of the peers proxy to disable the listener.
Unfortunately the bind_proc is left to 0 if no stick-table were used in
the configuration, stopping the listener on all processes.

This fixes sets the bind_proc to the first process if it wasn't
initialized.

Should fix bug #558. Should be backported as far as 1.8.

(cherry picked from commit a2cfd7e356f4d744294b510b05d88bf58304db25)
Signed-off-by: Willy Tarreau <w@1wt.eu>