use drone secrets for s3 info (#121)

Reviewed-on: https://gitea.com/gitea/theme/pulls/121

.drone.yml

@@ -18,11 +18,18 @@ steps:
 
 - name: release
   pull: always
-  image: plugins/s3
+  image: woodpeckerci/plugin-s3:latest
   settings:
-    bucket: gitea-artifacts
-    endpoint: https://ams3.digitaloceanspaces.com
-    path_style: true
+    acl:
+      from_secret: aws_s3_acl
+    region:
+      from_secret: aws_s3_region
+    bucket:
+      from_secret: aws_s3_bucket
+    endpoint:
+      from_secret: aws_s3_endpoint
+    path_style:
+      from_secret: aws_s3_path_style
     strip_prefix: dist/
     source: dist/master.tar.gz
     target: /theme