Use url.PathEscape to escape the branchname

[zeripath]

It is currently not possible to push a branch containing a % in it's name as it causes the internal protected branch checking api to return an error.

This code protects the branchname with url.PathEscape

[codecov-io]

Codecov Report

Merging #6304 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #6304      +/-   ##
==========================================
- Coverage   38.82%   38.81%   -0.01%     
==========================================
  Files         359      359              
  Lines       51100    51100              
==========================================
- Hits        19838    19836       -2     
- Misses      28391    28393       +2     
  Partials     2871     2871

Impacted Files	Coverage Δ
models/repo_list.go	66.84% <0%> (-1.06%)	⬇️

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