Don't attempt to repair readonly tables/views in information_schema.
DBManager: Don't attempt to repair tables in information_schema.

The tables (and views) in the information_schema database are all
virtual and all read-only. Any attempt to run repair table on them
will cause errors to be thrown.

Fixes self test failures.
Merge branch 'patches/bug6069' into devel

* patches/bug6069:
  DBManager: Don't attempt to repair tables in information_schema.