Fixed library install from git-url when reference points to a git branch

[cmaglie]

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What kind of change does this PR introduce?

Fixes library install from git-url when reference points to a git branch.

What is the current behavior?

Using the --git-url option with a specific branch gives error

Error installing Git Library: Library install failed: reference not found

What is the new behavior?

Library installs correctly

Does this PR introduce a breaking change, and is titled accordingly?

No

Other information

Fix #2825

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 67.76%. Comparing base (a2eebcd) to head (ef4a5f4).
Report is 10 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2833      +/-   ##
==========================================
+ Coverage   67.74%   67.76%   +0.02%     
==========================================
  Files         238      238              
  Lines       22410    22402       -8     
==========================================
  Hits        15181    15181              
+ Misses       6034     6029       -5     
+ Partials     1195     1192       -3     

Flag	Coverage Δ
unit	67.76% <100.00%> (+0.02%)	⬆️

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