Modify regex to capture right element

inc/Engine/Media/AboveTheFold/Frontend/Controller.php

@@ -142,7 +142,7 @@ private function set_fetchpriority( $lcp, string $html ): string {
 
 		$url  = preg_quote( $lcp->src, '/' );
 		$html = preg_replace_callback(
-			'#<img(?:[^>]*?\s+src=["\']' . $url . '["\'][^>]*?|[^>]*?)>#',
+			'#<img(?:[^>]*?\s+)?src=["\']' . $url . '["\'](?:\s+[^>]*?)?>#',
 			function ( $matches ) {
 				// Check if the fetchpriority attribute already exists.
 				if ( preg_match( '/fetchpriority\s*=\s*[\'"]([^\'"]+)[\'"]/i', $matches[0] ) ) {