network: Ignore 'mac' attribute on interfaces.

  A given 'mac' attribute is used to rename interfaces according to their MAC
  address to the given name. This is done by systemd link files (previously
  with udev rules). The MAC therefore isn't needed within the interfaces file.

  The attribute used to set a MAC address on an interface is 'hwaddress'. This
  is used to set MACs for B.A.T.M.A.N. interfaces.

Signed-off-by: Maximilian Wilhelm <max@sdn.clinic>

network/interfaces/interfaces.tmpl

@@ -69,7 +69,7 @@ iface {{ interface }}
     {%- set argument = config.get (keyword) %}
     {%- if argument is none %}
     {%- elif keyword.startswith ("_") %}
-    {%- elif keyword in [ 'auto', 'batman', 'bond', 'bridge', 'method', 'vlan', 'vxlan', 'desc', 'prefixes', 'status', 'tagged_vlans', 'has_gateway' ] %}
+    {%- elif keyword in [ 'auto', 'batman', 'bond', 'bridge', 'mac', 'method', 'vlan', 'vxlan', 'desc', 'prefixes', 'status', 'tagged_vlans', 'has_gateway' ] %}
     {%- elif argument is string or argument is number %}
 	{{ keyword }} {{ argument }}
     {%- else %}