gitweb: fix esc_url

Earlier, 452e225 (gitweb: fix esc_param, 2009-10-13) fixed CGI escaping
rules used in esc_url.  A very similar logic exists in esc_param and needs
to be fixed the same way.

Signed-off-by: Pavan Kumar Sunkara <pavan.sss1991@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

gitweb/gitweb.perl

@@ -1173,8 +1173,7 @@ sub esc_param {
 sub esc_url {
 	my $str = shift;
 	return undef unless defined $str;
-	$str =~ s/([^A-Za-z0-9\-_.~();\/;?:@&=])/sprintf("%%%02X", ord($1))/eg;
-	$str =~ s/\+/%2B/g;
+	$str =~ s/([^A-Za-z0-9\-_.~();\/;?:@&= ]+)/CGI::escape($1)/eg;
 	$str =~ s/ /\+/g;
 	return $str;
 }