inc: allow one-port setups for easier development

A one-port setup is essentially WAN-only.  The good thing is
the GUI attaches to the WAN port and is automatically reachable.
This helps with general testing of all things around builds.

While there, append a whitespace that has been missing for years.

etc/inc/config.console.inc

@@ -224,8 +224,7 @@ EOD;
 			}
 			
 			if($lanif == "") {
-				fclose($fp);
-				return;
+				break;
 			}
 	
 			if ($lanif === "a")