Increase sleep before restarting bgp on leaf switches otherwise default route is missing (#262)

Author: mwindower

Makefile

@@ -63,7 +63,7 @@ up: env gen-certs control-plane-bake partition-bake
 	ssh -F files/ssh/config leaf01 'systemctl restart metal-core'
 	ssh -F files/ssh/config leaf02 'systemctl restart metal-core'
 # TODO: for community SONiC versions > 202311 a bgp restart is needed in the virtual environment
-	sleep 10
+	sleep 15
 	ssh -F files/ssh/config leaf01 'systemctl restart bgp'
 	ssh -F files/ssh/config leaf02 'systemctl restart bgp'