Overwriting file in not possible on web if there is enough quota

[ScharfViktor]

ownCloud Web UI 6.0.0-rc.6
Infinite Scale 2.0.0-rc.1+736f513cf Community -local

Steps see this api test:

• https://github.com/owncloud/ocis/blob/master/tests/acceptance/features/apiSpaces/quota.feature#L56-L60
• create project space with quota = 10 curl -k -X POST 'https://localhost:9200/graph/v1.0/drives' -u admin:admin -d '{"name":"marketing", "quota": {"total": 10}}' -vk
• upload file 9 Bytes (if you created file- you need reload page Quota is not displayed after the creation of the project space and does not change after some operations #7959 )
• change this file on your PC to 5 bytes and upload it again

Actual: web checking

but it is possible.

Expect: The web check appears after clicking the "Keep Both" button. If we choose "merging" - it should be possible to overwrite

[JammingBen]

Has been fixed via #8015.