Catch OSError in BlockingConnectionPool.get_connection

[elemoine]

Pull Request check-list

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• Does $ tox pass with this change (including linting)?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is the new or changed code fully tested?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)? doesn't apply
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Description of change

This PR follows up on #1832. It applies the same fix to the BlockingConnectionPool.

[codecov-commenter]

Codecov Report

Merging #2001 (47c7fed) into master (e3c989d) will increase coverage by 0.02%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #2001      +/-   ##
==========================================
+ Coverage   92.94%   92.96%   +0.02%     
==========================================
  Files          78       78              
  Lines       16785    16785              
==========================================
+ Hits        15600    15604       +4     
+ Misses       1185     1181       -4     

Impacted Files	Coverage Δ
redis/connection.py	86.45% <0.00%> (ø)
tests/test_cluster.py	98.42% <0.00%> (+0.25%)	⬆️

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