Try fix of plagiarism check: non-UTF-8 title

submissions/plagiarism.py

@@ -89,7 +89,7 @@ class iThenticate:
             folder_id,
             author.user.first_name,
             author.user.last_name,
-            submission.title,
+            str(submission.title, 'utf-8'),
         )
 
         if response['status'] == 200: