[bgp]: Auto-completion, help (?), cmd navigation (up arrow) not working in vtysh on host system. (sonic-net#1124)

Author: nikos-github

dockers/docker-fpm-frr/base_image_files/vtysh

@@ -1,2 +1,2 @@
 #!/bin/bash
-docker exec -i bgp vtysh "$@"
+docker exec -it bgp vtysh "$@"

dockers/docker-fpm-quagga/base_image_files/vtysh

@@ -1,2 +1,2 @@
 #!/bin/bash
-docker exec -i bgp vtysh "$@"
+docker exec -it bgp vtysh "$@"