Fix a bug with timeout error handling

[PeterHamilton]

This change updates how the server handles SSL/TLS timeout errors when reading incoming client requests. Timeouts are now interpreted as session ending events, resulting in a closed connection as opposed to the original recurring error log message that was produced.

[codecov-io]

Codecov Report

Merging #441 into master will decrease coverage by 0.01%. The diff coverage is 50%.

@@            Coverage Diff             @@
##           master     #441      +/-   ##
==========================================
- Coverage   95.07%   95.06%   -0.02%     
==========================================
  Files          75       75              
  Lines       12671    12674       +3     
==========================================
+ Hits        12047    12048       +1     
- Misses        624      626       +2

Impacted Files	Coverage Δ
kmip/services/server/session.py	98.63% <50%> (-1.37%)	:arrow_down:

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