fix ST_PolygonFromEnvelope bug

[neza2017]

##What type of PR is this?

bug

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #554

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Additional documentation (e.g. design docs, usage docs, etc.):

[codecov]

Codecov Report

Merging #557 into branch-0.1.x will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@              Coverage Diff              @@
##           branch-0.1.x     #557   +/-   ##
=============================================
  Coverage         95.97%   95.97%           
=============================================
  Files                85       85           
  Lines              9113     9114    +1     
=============================================
+ Hits               8746     8747    +1     
  Misses              367      367           

Flag	Coverage Δ
#amd64_linux_gpu_unittest	95.97% <100.00%> (+<0.01%)	⬆️

Impacted Files	Coverage Δ
cpp/src/gis/gdal/gis_functions.cpp	91.54% <100.00%> (+0.01%)	⬆️

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