Remove port 22 from webservers extra ports

This isn't necessary since it's hard-coded into the file.  Let's
not add it where it isn't needed lest we confuse ourselves into
thinking it's necessary.

Change-Id: I011c647bb85e145e55fb6feb19facdedec180bf1

inventory/service/group_vars/webservers.yaml

@@ -1,4 +1,3 @@
 iptables_extra_public_tcp_ports:
-  - 22
   - 80
   - 443