Avoid repeated initialization when clicking very fast

There is potentially a lot of time between when the attribute is
checked and when it is finally set. At least the two RessourceLoader
modules need to load. This can take a while, even on fast internet
connections. Just double clicking with the mouse can trigger the code
twice without the attribute being set.

The proposed solution is not the only one, but I believe moving this
single line is the most trivial one.

Bug: T358637
Change-Id: Ic9b99859841439febb83e91f70930e8676a4968a

resources/js/ext.uls.interface.js

@@ -578,6 +578,7 @@
 		if ( $target.attr( 'data-uls-loaded' ) ) {
 			return;
 		}
+		$target.attr( 'data-uls-loaded', true );
 
 		ev.preventDefault();
 
@@ -588,8 +589,6 @@
 			languageNodes = parent ? parent.querySelectorAll( '.interlanguage-link-target' ) : [];
 			standalone = isUsingStandaloneLanguageButton();
 
-			$target.attr( 'data-uls-loaded', true );
-
 			// Setup click handler for ULS
 			launchULS(
 				$target,