lib, bgpd: Disallow processing of duplicate config.

lib, bgpd: Disallow processing of duplicate config.

This fix aims to reduce the load on BGPD when certain
exisiting configurations are replayed.
Specifically, the fix prevents BGPD from processing
routes when the following already existing configurations
are replayed:
1) A match criteria is configured within a route-map.
2) When "call" is invoked within a route-map.
3) When a route-map is tied to a BGP neighbor.

Signed-off-by: NaveenThanikachalam <nthanikachal@vmware.com>