Issue 4432 - After a failed online import the next imports are very slow

Bug Description:  When an online import fails the entry and DN caches are
                  "reset", but we use the wrong "new maxsize" which was
                  setting the entry cache maxsize to zero which killed the
                  import performance.

Fix Description:  When resetting the caches use the previous cache maxsize.

Relates: #4432

Reviewed by: firstyear & progier(Thanks!!)