Remove tripleo_hostname tag

The tags field in neutron has a max length of
60 characters. A hostname can be longer, and in
the case it is longer adding the tag will cause
a "Invalid input exceeds maximum length of 60"
error will be raised.

Related-Bug: #1921713
Change-Id: I72fd4a9575482389900145a03a6142cccd1111ba

network/ports/port.j2

@@ -94,10 +94,6 @@ resources:
         - get_param: FixedIPs
       replacement_policy: AUTO
       tags:
-        - str_replace:
-            template: tripleo_hostname=$HOSTNAME
-            params:
-              $HOSTNAME: {get_param: DnsName}
         - str_replace:
             template: tripleo_stack_name=$STACK_NAME
             params: