Removes server_port from request_info

[shadowbrush]

Proposed changes

Remove server_port from request_info.

Resolve issue #609 - Stop passing server_port to python3-saml

server_port has been deprecated by python3-saml, see: SAML-Toolkits/python3-saml#276

If the server application is running behind a load balancer or a reverse proxy the request port might not match the SAML configuration.

Types of changes

Please check the type of change your PR introduces:

• Release (new release request)
• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (PEP8, lint, formatting, renaming, etc)
• Refactoring (no functional changes, no api changes)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Build related changes (build process, tests runner, etc)
• [ x] Other (please describe): Changes in reaction to a deprecation in dependency

Checklist

Put an x in the boxes that apply. You can also fill these out after creating
the PR. If you're unsure about any of them, don't hesitate to ask. We're here to
help! This is simply a reminder of what we are going to look for before merging
your code.

• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works

Other information

Any other information that is important to this PR such as screenshots of how
the component looks before and after the change.

[codecov]

Codecov Report

Merging #671 (6c20b8e) into master (0fccfde) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #671      +/-   ##
==========================================
- Coverage   76.95%   76.94%   -0.02%     
==========================================
  Files         317      317              
  Lines        9648     9648              
  Branches     1034     1034              
==========================================
- Hits         7425     7424       -1     
- Misses       2071     2072       +1     
  Partials      152      152              

Flag	Coverage Δ
unittests	76.94% <ø> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
social_core/backends/saml.py	80.31% <ø> (ø)
social_core/tests/strategy.py	93.84% <0.00%> (-1.54%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0fccfde...6c20b8e. Read the comment docs.

[nijel]

Merged, thanks for your contribution!