Merge branch '3.1.1_release' into 'master'

v3.1.1

See merge request oceanbase/ob-deploy!275

Author: 雪染

plugins/ocp-server/4.2.1/upgrade.py

@@ -57,5 +57,7 @@ def upgrade(plugin_context, search_py_script_plugin, apply_param_plugin, run_wor
     if not run_workflow(start_workflows, repositories=[dest_repository], **{dest_repository.name: start_kwargs}):
         return plugin_context.return_false()
     upgrade_ctx = kwargs.get('upgrade_ctx')
-    upgrade_ctx['index'] += 1
+    if upgrade_ctx:
+        if upgrade_ctx.get('index'):
+            upgrade_ctx['index'] += 1
     return plugin_context.return_true()