Remove unused modulesync parameter githubUrl

The modulesync template
(https://github.com/projectsyn/modulesync-control), doesn't use the
`githubUrl` parameter anymore.

This commit removes the parameter from the initial modulesync config
generated by `commodore component new`.

commodore/component-template/{{ cookiecutter.slug }}/.sync.yml

@@ -1,6 +1,5 @@
 :global:
   componentName: {{ cookiecutter.name }}
-  githubUrl: {{ cookiecutter.github_url }}
   feature_goldenTests: true
 
 docs/antora.yml: