Folds two identical exception handlers into a single one

Folds two identical exception handlers into a single one

Fixes a `TODO` that searches for py2/3 compatible syntax to match multiple exception types.

### Description

Merges the two exception clauses using the syntax that exists for both Python 2 and 3 as per the exception handling tutorials ([Python 2](https://docs.python.org/2/tutorial/errors.html#handling-exceptions), [Python 3](https://docs.python.org/3/tutorial/errors.html#handling-exceptions))

### Checklist

This pull request is:

- [ ] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [x] A short code fix
	- please include the issue number, and create an issue if none exists, which
	  must include a complete example of the issue.  one line code fixes without an
	  issue and demonstration will not be accepted.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.   one line code fixes without tests will not be accepted.
- [ ] A new feature implementation
	- please include the issue number, and create an issue if none exists, which must
	  include a complete example of how the feature would look.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.

**Have a nice day!**

Closes: #5325
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5325
Pull-request-sha: d0835511e5509fb368a2193ebe4ecbbe3504b129

Change-Id: If3a8854e4de023e0ec68ae8649d24af9412f0717