set pipeline condition

.woodpecker.yml

@@ -1,4 +1,8 @@
 pipeline:
+  when:
+    event: tag
+    branch: main     
+
   print-variable:
     image: alpine
     commands:
@@ -23,6 +27,4 @@ pipeline:
       password:
         from_secret: docker_password
         
-when:
-  event: tag
-  branch: main      
+