Add a CLI command that creates an empty LDAP config

[mark0n]

This is needed to configure the user_ldap app without using the
wizard (e.g. using tools like Puppet).

[ghost]

Thanks a lot for your contribution! Contributions to the core repo require a signed contributors agreement http://owncloud.org/contribute/agreement/ Alternatively you can add a comment here stating that this contribution is MIT licensed. Some more details about out pull request workflow can be found here: http://owncloud.org/code-reviews-on-github/

[scrutinizer-notifier]

The inspection completed: 4 new issues, 4 updated code elements

[MorrisJobke]

cc @blizzz

[blizzz]

Thank you for your contribution! :)

Tested, works and looks good 👍

@mark0n could you comment on #11347 (comment)?

[blizzz]

@owncloud-bot this is ok to test

[ghost]

🚀 Test PASSed. 🚀
Refer to this link for build results (access rights to CI server needed):
https://ci.owncloud.org//job/pull-request-analyser/7610/

[mark0n]

I emailed a signed copy of the contributor agreement to Frank last night.

[LukasReschke]

@karlitschek Can you confirm? THX.

[karlitschek]

confirmed :-)

[LukasReschke]

👍