Fixed connection pooling tests for more than one ODBC drivers

[yitam]

This change is 

[coveralls]

Coverage remained the same at 74.706% when pulling d554492 on yitam:connPooltests into ea6381c on Microsoft:dev.

[codecov-io]

Codecov Report

Merging #796 into dev will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev     #796   +/-   ##
=======================================
  Coverage   80.06%   80.06%           
=======================================
  Files          25       25           
  Lines        7325     7325           
=======================================
  Hits         5865     5865           
  Misses       1460     1460

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