Clone wiki only for steps which need it

[mathbunnyru]

This change is to address the situation in #1341 (also happened with me once).

Now we can't merge to the master if there is something in the master which is not yet built.
This will cause errors.
The reason for that is that in the docker builds we clone the wiki in the beginning, and at the end of the build update the wiki.
And in between, we build the images (it's a long step that takes more than 30 minutes now).
And then there will be two commits in the docs which change the docs in a different way.
So, the second build will not update wiki (manifests).
And so the CI will fail.

This commit uses wiki only for a minute:

• clone wiki (seconds)
• hook everything (1min15s)
• push wiki if it's master (seconds)

This way we lock the wiki only for a minute, so we have much more chances with the situation like I described.

[mathbunnyru]

This prevents from the master merge errors, so let give this a try, I think this is a good change.