Remove errant newline from system hooks documentation

[ci skip]

Remove errant newline from system hooks documentation
[ci skip]
4b4b34c2 · Robert Speicher · 7f3ff241 · 4b4b34c2
--- a/doc/system_hooks/system_hooks.md
+++ b/doc/system_hooks/system_hooks.md
@@ -504,7 +504,7 @@ X-Gitlab-Event: System Hook
      "force_remove_source_branch": "0"
    },
    "merge_when_pipeline_succeeds": false,
-    "merge_user_i\nd": null,
+    "merge_user_id": null,
    "merge_commit_sha": null,
    "deleted_at": null,
    "in_progress_merge_commit_sha": null,