Bugfix: Fix the ocm gateway connection pool

Fix the ocm gateway connection pool.
Fix ocis dependency in the reva go.mod file. Bump the ocis version accordingly to the major version.

https://github.com/owncloud/ocis/pull/10916
https://github.com/owncloud/ocis/issues/10846
https://github.com/owncloud/ocis/issues/10878
