Fix album_artist substitution

For albums that are listed with a non-"main" artist first (ex: 37691520), the album artist replacement was returning an empty string. This isn't a problem with the default settings, but if you format albums into `{album_artist}/...`, the path becomes `/...` in this case, and is interpreted as an absolute path instead of a relative one, causing the download to fail.

This changes the logic so that if the `first_only` flag is passed, it will return after the first artist is actually added to the list, no longer returning an empty string.

tidal_dl_ng/helper/tidal.py

@@ -45,8 +45,8 @@ def name_builder_album_artist(media: Track | Album, first_only: bool = False, de
         if Role.main in artist.roles:
             artists_tmp.append(artist.name)
 
-        if first_only:
-            break
+            if first_only:
+                break
 
     return delimiter.join(artists_tmp)