Revert "ownCloud: add support for client"

This reverts commit e82fd0717ede27fb4c8dd0fcdf74c7eef82307d3.
Rename function argument

Use uri instead of path or location
Fixes 734817
Mail: Initial support for using email as storage
Mail: filter all accounts that enable email

but still not create / add mail provider according these accounts
Merge branch 'wip/mail-provider' of https://github.com/xuchunyang/bijiben into wip/mail-provider
Mail: Fix a logic error