Fix a DeprecationWarning about __getitem__() and exceptions in the 'traceback' module.

git-svn-id: http://svn.python.org/projects/python/trunk@65346 6015fed2-1504-0410-9fe1-9d1591cc4771

Author: brett.cannon

Diff for: Lib/traceback.py

@@ -181,7 +181,7 @@ def format_exception_only(etype, value):
     # It was a syntax error; show exactly where the problem was found.
     lines = []
     try:
-        msg, (filename, lineno, offset, badline) = value
+        msg, (filename, lineno, offset, badline) = value.args
     except Exception:
         pass
     else: