Update API GW stage settings only when explicitly set

[medikoo]

Fixes #6165

If given APIGW stage parameter is not explicitly set in configuration, then it should not be updated by deployment.

[codecov-io]

Codecov Report

Merging #7033 into master will decrease coverage by <.01%.
The diff coverage is 84%.

@@            Coverage Diff             @@
##           master    #7033      +/-   ##
==========================================
- Coverage    88.5%   88.49%   -0.01%     
==========================================
  Files         229      229              
  Lines        8428     8433       +5     
==========================================
+ Hits         7459     7463       +4     
- Misses        969      970       +1

Impacted Files	Coverage Δ
.../compile/events/apiGateway/lib/hack/updateStage.js	95.86% <84%> (-0.57%)	⬇️

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[pmuens]

Just looked through the code. Looks good (haven't tested it manually, though)...

LGTM

[medikoo]

Just looked through the code. Looks good (haven't tested it manually, though)...

I've run all integration tests against it to confirm, all passed well