T938: do not bind DHCP relay to default port if unspecified

Binding isc-dhcp-relay to its default port (67 e.g. for IPv4) will
result in an error when starting up the service:

bad:
----
$ dhcrelay -q -4 -p 67 -c 10 -A 576 -m discard -i eth0.21 -i eth0 10.253.253.1
binding to user-specified port 67

good:
-----
$ dhcrelay -q -4 -c 10 -A 576 -m discard -i eth0.21 -i eth0 10.253.253.1

Setting removed from the IPv6 implementation, too!

1 files changed, 2 insertions, 2 deletions

diff --git a/src/conf_mode/dhcpv6_relay.py b/src/conf_mode/dhcpv6_relay.py
index c8b3eca6d..959bf0496 100755
--- a/src/conf_mode/dhcpv6_relay.py
+++ b/src/conf_mode/dhcpv6_relay.py
@@ -31,13 +31,13 @@ config_tmpl = """
 
 # Defaults for isc-dhcpv6-relay initscript sourced by /etc/init.d/isc-dhcpv6-relay
 
-OPTIONS="-6 -l {{ listen_addr | join('-l ') }} -p {{ port }} {{ options | join(' ') }} -u {{ upstream_addr | join('-u ') }}"
+OPTIONS="-6 -l {{ listen_addr | join('-l ') }} {% if port -%} -p {{ port }}{%- endif %} {{ options | join(' ') }} -u {{ upstream_addr | join('-u ') }}"
 """
 
 default_config_data = {
     'listen_addr': [],
     'upstream_addr': [],
-    'port': '547',
+    'port': '',
     'options': [],
 }