Revert followup change for #337585 -- the only thing an empty macro should...

Revert followup change for #337585 -- the only thing an empty macro should return is the autogenerated id.

gmap_parse_macro.inc

@@ -262,10 +262,6 @@ function _gmap_parse_macro($instring, $ver = 2) {
     }
     unset($m['behavior-temp']);
   }
-  else {
-    // Inherit site default behavior.
-    $m['behavior'] = $def['behavior'];
-  }
 
   // tcontrol now is mtc.
   if (isset($m['tcontrol'])) {