git-svn: convert CRLF to LF in commit message to SVN

Subversion since 1.6 does not accept CR characters in the commit
message, so filter it out on our end before 'git svn dcommit' sets
the svn:log property.

Reported-by: Brian Bennett <Brian.Bennett@Transamerica.com>
Signed-off-by: Eric Wong <e@80x24.org>

git-svn.perl

@@ -1865,6 +1865,7 @@ sub get_commit_entry {
 			}
 		}
 		$msgbuf =~ s/\s+$//s;
+		$msgbuf =~ s/\r\n/\n/sg; # SVN 1.6+ disallows CRLF
 		if ($Git::SVN::_add_author_from && defined($author)
 		    && !$saw_from) {
 			$msgbuf .= "\n\nFrom: $author";