fix: drone

.drone.yml

@@ -5,6 +5,7 @@ clone:
 build:
   image: docker.i2edu.net/golang:1.13
   commands:
+    - go env -w GOPROXY=https://goproxy.cn,direct
     - go mod tidy
     - CGO_ENABLED=0 go build -a -ldflags '-s'
     - tar zcf i2-bill-erp.tar.gz etc i2-bill-erp