Invoke external script that creates image file as user "nobody" since

otherwise the file is created as that user, and is then difficult to
remove in floormap_aux.php3 after it is dished out. There is no reason
to run the external script as the user; all it does is build an image.

www/floormap.php3

@@ -155,7 +155,7 @@ if (!preg_match("/^\/tmp\/([-\w]+)$/", $prefix, $matches)) {
 }
 $uniqueid = $matches[1];
 
-$retval = SUEXEC($uid, "nobody", "webfloormap -o $prefix " .
+$retval = SUEXEC("nobody", "nobody", "webfloormap -o $prefix " .
 		 (isset($pid) ? "-e $pid,$eid " : "") .
 		 (isset($floor) ? "-f $floor " : "") .
 		 (isset($building) ? "$building" : ""),