Fix branch in instancejson pipeline

Signed-off-by: Odyssey <hi@odyssey346.dev>

.woodpecker/instancejson.yml

@@ -25,4 +25,4 @@ pipeline:
       - git config --global user.name "Woodpecker CI"
       - git add instances.json
       - git commit -m "Updated instances"
-      - git push -u origin dev
+      - git push -u origin master