Increase performance of auto_delete queues deletion on channel down

[dcorbacho]

Re-introduce previous delete guard for auto_delete queues.
Undo performance enhancement introduced by #1513 for this use case.
All other bulk deletions remain the same.

Types of Changes

• Bugfix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (correction or otherwise)
• Cosmetics (whitespace, appearance)

Checklist

• I have read the CONTRIBUTING.md document
• I have signed the CA (see https://cla.pivotal.io/sign/rabbitmq)
• All tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in related repositories

[acogoluegnes]

I couldn't reproduce the issue whereby client topology recovery kicks in when auto-deletion of queues isn't finished, resulting in errors during binding and consumer recovery because queues have been deleted meanwhile. Looks good to me, well done @dcorbacho!