Remove redundant assignment in .../engine/create.py
Remove redundant assignment in .../engine/create.py

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### Description
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Remove a redundant assignment in the engine creation file.

### Checklist
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This pull request is:

- [x] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [ ] 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: #4944
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4944
Pull-request-sha: 4a0e6206f0ae5ff5350ecaa6f998bc3dc0c26cdd

Change-Id: Ie491b071e3392334947d3b8ba84c7323c1b15b6e

graingert/sqlalchemy,sqlalchemy/sqlalchemy,j5int/sqlalchemy,zzzeek/sqlalchemy,graingert/sqlalchemy,monetate/sqlalchemy,j5int/sqlalchemy,monetate/sqlalchemy