Fix memory leak

* Return after setting the error for advanced features without
  libraqm. Not returning here leads to an alloc that's never freed.

src/_imagingft.c

@@ -425,6 +425,7 @@ text_layout_fallback(
             "setting text direction, language or font features is not supported "
             "without libraqm"
         );
+        return 0;
     }
 
     if (PyUnicode_Check(string)) {