Add role for gtw node without tagging br-mesh
Change single_ovs_br_floating to be able to use IP provided in
environment context

Change-Id: I0b69ab83d446b4ad365610715aca33c5c07257d0
diff --git "a/\173\043 interfaces \043\175/single_ovs_br_floating" "b/\173\043 interfaces \043\175/single_ovs_br_floating"
index 3f8281d..b66b73d 100644
--- "a/\173\043 interfaces \043\175/single_ovs_br_floating"
+++ "b/\173\043 interfaces \043\175/single_ovs_br_floating"
@@ -30,9 +30,9 @@
                 {%- if 'mtu' in interface %}
                 mtu: {{ interface['mtu'] }}
                 {%- endif %}
-                address: ${_param:external_address}
+                address: ${_param:_esc}{_param:external_address}
                 netmask: 255.255.255.0
                 use_interfaces:
                 - {{ interface_name }}
                 use_ovs_ports:
-                - float-to-ex
\ No newline at end of file
+                - float-to-ex