Fix upgrade-script not expecting additional parameter

With commit [1], a new upgrade script was included, but since
it is not expecting the new port parameter it broke the new USM
feature "software deploy start".

This commit fixes the issue.

[1] https://review.opendev.org/c/starlingx/config/+/909866

Test Plan
PASS: run software deploy start successfully

Story: 2010676
Task: 49699

Change-Id: I79101b53e6c335ed9fe5b412ca029d1c17df3cea
Signed-off-by: Heitor Matsui <heitorvieira.matsui@windriver.com>

controllerconfig/controllerconfig/upgrade-scripts/29-mgmt-network-fqdn-reconfig.py

@@ -71,6 +71,10 @@ def main():
             to_release = sys.argv[arg]
         elif arg == 3:
             action = sys.argv[arg]
+        elif arg == 4:
+            # optional port parameter for USM upgrade
+            # port = sys.argv[arg]
+            pass
         else:
             LOG.error("Invalid option %s." % sys.argv[arg])
             return 1