Add toggle for publishing to master servers

entrypoint.sh

@@ -12,6 +12,9 @@ if [ -n "$RCON_PASSWORD" ]; then
   echo "set sv_rconpassword $RCON_PASSWORD" >> /srv/server.cfg
 fi
 
+UPDATE_MASTER=${UPDATE_MASTER:-true}
+echo "set sv_updatemaster $UPDATE_MASTER" >> /srv/server.cfg
+
 # As of Zandrodum 3.0.0 we have to use `+addbot` instead using server.cfg
 # https://zandronum.com/forum/viewtopic.php?t=8073<Paste>
 ADDBOT_CMDS=""