t5813: do not use UNC paths

In Windows, a double slash in the beginning of an absolute path denotes
network paths of the form `\\localhost\share\file`. In Git for Windows'
context, the same form is also available with forward slashes.

Let's not start the path in the URL with a double slash (e.g.
`ssh://host//usr/src/git/t/file`) but take pains to use the normalized
form with a single slash, so that Git is not confusing the path for a
UNC one.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

t/t5813-proto-disable-ssh.sh

@@ -14,7 +14,7 @@ test_expect_success 'setup repository to clone' '
 '
 
 test_proto "host:path" ssh "remote:repo.git"
-test_proto "ssh://" ssh "ssh://remote/$PWD/remote/repo.git"
-test_proto "git+ssh://" ssh "git+ssh://remote/$PWD/remote/repo.git"
+test_proto "ssh://" ssh "ssh://remote$PWD/remote/repo.git"
+test_proto "git+ssh://" ssh "git+ssh://remote$PWD/remote/repo.git"
 
 test_done