git svn: avoid escaping '/' when renaming/copying files

git svn: avoid escaping '/' when renaming/copying files

Timothy Schaeffer reported the following:
> Git-svn has been giving me the following error for some time
> when calling "git svn dcommit":
>
> RA layer request failed: PROPFIND request failed on
> '/svn/stf/branches/dev/sw%2Fdpemu%2Finclude%2FNetCnxn.h': PROPFIND of
> '/svn/stf/branches/dev/sw%2Fdpemu%2Finclude%2FNetCnxn.h': 302 Found
> (https://oursvnrepo.net) at /usr/local/libexec/git-core/git-svn line 508
>
> This only occurred when git detected a rename or copy.
>
> Following the lead into git-svn.perl,
> and noticing that some of the '/'s in the path were hex-encoded
> and some were not,
> I changed the regex used to find chars
> to hex-encode in the relative part of the path
> to exclude '/'.
> It works, so far.
> I have included a patch.

While this has previous not been a problem in my experience,
newer versions of SVN may be stricter and this does not
introduce regressions in t9115.

Signed-off-by: Eric Wong <normalperson@yhbt.net>