t5500-fetch-pack.sh test failures

[me-and]

Bisect on the main repo points to this failure being added by ebb8d2c90f ("mingw: support UNC in git clone file://server/share/repo"). That commit changes both function and tests; running the new function with the old tests also fails, which rather implies this is a genuine regression.

[me-and]

https://github.com/git/git/blob/master/t/t5500-fetch-pack.sh#L762-L781 looks wrong to me: it's using $h with a value left over from a previous loop rather than one that's set in the containing loop. I don't think that's the cause of the failures here, but it certainly can't be helping anything.