fix ocm-provider rewrite rules

[ArtificialOwl]

Fix the rewrite rules about ocm-provider in 2 locations:

• the default .htaccess,
• the generated part of htaccess from Setup.php

I were only able to reproduce the issue in some conditions, each time it seems that this patch fixed them.

[Altahrim]

Not tested, but LGTM

[nickvergessen]

@ArtificialOwl can you install an older version and then update, to see if the htaccess change is correctly handled by the updater?

[blizzz]

/backport to stable27

[blizzz]

/backport to stable26

[backportbot-nextcloud]

The backport to stable27 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable27
git pull origin stable27

# Create the new backport branch
git checkout -b fix/foo-stable27

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable27

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport