Fix LFS Locks over SSH

[zeripath]

Whilst looking at adding more tests for #6993 I've noticed that LFS locking was not-preauthenticating correctly over SSH.

This PR fixes this.

Fixes #3084

[lunny]

It seems there is an issue reported that.

[zeripath]

@lunny do you know which issue it is because I can't seem to easily find it.

[lunny]

Maybe it is #5478

[zeripath]

It's possible that this is part of the fix for that, but I think #6993 is probably more likely to fix that.

I'm going to incorporate this in #6993 in any case.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@27b271d). Click here to learn what that means.
The diff coverage is 54.32%.

@@            Coverage Diff            @@
##             master    #6999   +/-   ##
=========================================
  Coverage          ?   41.43%           
=========================================
  Files             ?      442           
  Lines             ?    59693           
  Branches          ?        0           
=========================================
  Hits              ?    24731           
  Misses            ?    31725           
  Partials          ?     3237

Impacted Files	Coverage Δ
routers/routes/routes.go	82.68% <100%> (ø)
modules/lfs/locks.go	48.59% <53.75%> (ø)

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[sapk]

You need to use the Skip method in place of simple return in skipped tests. Overall looks good but I haven't tested yet.

[zeripath]

@sapk have you been able to test this yet? git_test.go does test the locking now btw.

[sapk]

@zeripath not much time to do so lately. So if someone other validate it should be good as my requested changes are done.

[lunny]

@zeripath I think this should resolve #7219, could you send back port to v1.8 .