Use a relative path for SVN importing

The absolute path (with the leading slash) breaks SVN importing,
because it then looks for /trunk/... instead of /svn/trunk/...
(in my case, the repository URL was https://servername/svn/)

Signed-off-by: Christian Biesinger <cbiesinger@web.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

git-svnimport.perl

@@ -318,7 +318,7 @@ ($$$)
 			die $res->status_line." at $url\n";
 		}
 	} else {
-		$name = $svn->file("/$svnpath",$rev);
+		$name = $svn->file("$svnpath",$rev);
 		return undef unless defined $name;
 	}