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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