Merge branch 'patch-45' into 'master'

Remove duplicate protected variable name in sample json

See merge request gitlab-org/gitlab!22074

doc/api/project_level_variables.md

@@ -86,7 +86,6 @@ curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" "https://gitla
     "value": "new value",
     "protected": false,
     "variable_type": "env_var",
-    "protected": false,
     "masked": false,
     "environment_scope": "*"
 }