git-svn: On MSYS, escape and quote SVN_SSH also if set by the user

While GIT_SSH does not require any escaping / quoting (e.g. for paths
containing spaces), SVN_SSH requires it due to its use in a Perl script.

Previously, SVN_SSH has only been escaped and quoted automatically if it
was unset and thus derived from GIT_SSH. For user convenience, do the
escaping and quoting also for a SVN_SSH set by the user. This way, the
user is able to use the same unescaped and unquoted syntax for GIT_SSH
and SVN_SSH.

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-svn.perl

@@ -22,14 +22,13 @@
 $Git::SVN::Ra::_log_window_size = 100;
 $Git::SVN::_minimize_url = 'unset';
 
-if (! exists $ENV{SVN_SSH}) {
-	if (exists $ENV{GIT_SSH}) {
-		$ENV{SVN_SSH} = $ENV{GIT_SSH};
-		if ($^O eq 'msys') {
-			$ENV{SVN_SSH} =~ s/\\/\\\\/g;
-			$ENV{SVN_SSH} =~ s/(.*)/"$1"/;
-		}
-	}
+if (! exists $ENV{SVN_SSH} && exists $ENV{GIT_SSH}) {
+	$ENV{SVN_SSH} = $ENV{GIT_SSH};
+}
+
+if (exists $ENV{SVN_SSH} && $^O eq 'msys') {
+	$ENV{SVN_SSH} =~ s/\\/\\\\/g;
+	$ENV{SVN_SSH} =~ s/(.*)/"$1"/;
 }
 
 $Git::SVN::Log::TZ = $ENV{TZ};