The blob test `commit_from_wrong_partition` makes use of the logger `ZODB.blob.copied`.

In some cases, this test fails not because the ZODB did something wrong but because the logger is disabled.

At least under Python 3.6, `logging.fileConfig` (and likely all other functions configuring the logging system) disables by default all existing loggers. If logger `ZODB.blob.copied` is already created at that time (i.e. if `ZODB.blob` has been imported), it gets disabled.

The PR adds `logger.disabled = False` to the test `commit_from_wrong_partition` to let it work correctly in those situations.