Correct git config item name in mirror-workspace-git-repos

It appears this setting inadvertently had an extra word "ignore"
included in the key name, and later versions of the git module in
Ansible (5) throw an error in that case.  Remove it so that this
role will work in all versions.

Change-Id: If008cc5b12efb23f731f99806ddfb69ce9bb5d15

roles/test-mirror-workspace-git-repos/tasks/main.yaml

@@ -1,6 +1,6 @@
 - name: Allow pushing to non-bare repo
   git_config:
-    name: receive.denyCurrentBranch ignore
+    name: receive.denyCurrentBranch
     value: ignore
     scope: local
     repo: "{{ ansible_user_dir }}/{{ zj_project.value.src_dir }}"