Omit include of no longer existing files
Warnings are generated during setup.py install such as:
```
Getting distribution for 'SQLAlchemy==1.2.15'.
warning: no files found matching '*.jpg' under directory 'doc'
warning: no files found matching '*.mako' under directory 'doc'
warning: no files found matching 'distribute_setup.py'
warning: no files found matching 'sa2to3.py'
warning: no files found matching 'ez_setup.py'
```
This change removes those expressions from MANIFEST.in.
Closes: #4408
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4408
Pull-request-sha:
448b3a9dc8f25d841f20bcd67130acaea68cb745
Change-Id: Id6373611fb384e230427f87b9e75672d78483000