Fixed #401

- Fixed high concurrency panic on slow geoIP resolve mode
- Added test case for concurrent geodb access

src/main.go

@@ -46,7 +46,6 @@ import (
 	"imuslab.com/zoraxy/mod/utils"
 )
 
-
 /* SIGTERM handler, do shutdown sequences before closing */
 func SetupCloseHandler() {
 	c := make(chan os.Signal, 2)