[BUG] orchestratorVersion should not get changed for ACS scale apiVersion 2017-07-01

[CecileRobertMichon]

What this PR does / why we need it: This is a regression since we started retiring k8s version. ACS needs to keep the previous version for update (upgrade is not supported for that apiversion).

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

If applicable:

• [ ] documentation
• [ ] unit tests
• [ ] tested backward compatibility (ie. deploy with previous version, upgrade with this branch)

Release note:

[codecov[bot]]

Codecov Report

Merging #4346 into master will decrease coverage by <.01%. The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #4346      +/-   ##
==========================================
- Coverage   55.45%   55.45%   -0.01%     
==========================================
  Files         109      109              
  Lines       16054    16053       -1     
==========================================
- Hits         8903     8902       -1     
  Misses       6368     6368              
  Partials      783      783

[codecov[bot]]

Codecov Report

Merging #4346 into master will decrease coverage by <.01%. The diff coverage is 77.77%.

@@            Coverage Diff             @@
##           master    #4346      +/-   ##
==========================================
- Coverage   55.45%   55.44%   -0.01%     
==========================================
  Files         109      109              
  Lines       16054    16055       +1     
==========================================
- Hits         8903     8902       -1     
- Misses       6368     6369       +1     
- Partials      783      784       +1

[jackfrancis]

/lgtm