Fix empty path TSR test case

copy & paste fail
diff --git a/router_test.go b/router_test.go
index 19aeb39..7c8ac09 100644
--- a/router_test.go
+++ b/router_test.go
@@ -180,7 +180,7 @@
 	}{
 		{"/path/", 301, "map[Location:[/path]]"},   // TSR -/
 		{"/dir", 301, "map[Location:[/dir/]]"},     // TSR +/
-		{"/dir", 301, "map[Location:[/dir/]]"},     // TSR +/
+		{"", 301, "map[Location:[/]]"},             // TSR +/
 		{"/PATH", 301, "map[Location:[/path]]"},    // Fixed Case
 		{"/DIR/", 301, "map[Location:[/dir/]]"},    // Fixed Case
 		{"/PATH/", 301, "map[Location:[/path]]"},   // Fixed Case -/