drone: change value of GOPROXY

May be related to golang/go#33513.

Author: fsouza

drone/.drone.jsonnet

@@ -61,7 +61,7 @@ local mod_download(go_version) = {
   name: 'mod-download',
   image: 'golang:%(go_version)s' % { go_version: go_version },
   commands: ['go mod download'],
-  environment: { GOPROXY: 'https://proxy.golang.org' },
+  environment: { GOPROXY: 'https://goproxy.io' },
   depends_on: ['clone'],
 };
 

drone/.drone.yml

@@ -16,7 +16,7 @@ steps:
   commands:
   - go mod download
   environment:
-    GOPROXY: https://proxy.golang.org
+    GOPROXY: https://goproxy.io
   depends_on:
   - clone
 
@@ -138,7 +138,7 @@ steps:
   commands:
   - go mod download
   environment:
-    GOPROXY: https://proxy.golang.org
+    GOPROXY: https://goproxy.io
   depends_on:
   - clone
 
@@ -214,7 +214,7 @@ steps:
   commands:
   - go mod download
   environment:
-    GOPROXY: https://proxy.golang.org
+    GOPROXY: https://goproxy.io
   depends_on:
   - clone