Check for no title/artist tag in replace_files

app/replace_files.py

@@ -75,7 +75,13 @@ def main():
             continue
         new_tags = get_tags(new_path)
         new_title = new_tags["title"]
+        if not new_title:
+            print(f"{new_fname} does not have a title tag")
+            sys.exit(1)
         new_artist = new_tags["artist"]
+        if not new_artist:
+            print(f"{new_fname} does not have an artist tag")
+            sys.exit(1)
         bitrate = new_tags["bitrate"]
 
         # If same filename exists in parent direcory, check tags