BUG-2400 : Added forgotten MAX_MSG_PER_READ option to BGP.

Change-Id: I690f2043a4c8a4d4ee9c48bf64c8841b1a704b16
Signed-off-by: Dana Kutenicsova <dkutenic@cisco.com>
(cherry picked from commit 0138d06f4c7ead1a472f846e4721df97fce15f3c)