Work around a driver that report indcols incorrectly

[cnliao]

I am using an SQL Server 2008 with ODBC Driver 17 for SQL Server from Microsoft.
It seems for varchar(200) columns it sets indcols to a value larger than 201, causing
a BoundsError. Use the lessor one of elsize and indcols to work around this.

[codecov-io]

Codecov Report

Merging #212 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #212   +/-   ##
=======================================
  Coverage   92.34%   92.34%           
=======================================
  Files           4        4           
  Lines         196      196           
=======================================
  Hits          181      181           
  Misses         15       15

Impacted Files	Coverage Δ
src/Query.jl	98.05% <ø> (ø)	⬆️

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