Fix for unencrypted uris in scrubber queue files

The scrubber can write unencrypted uris in queue files in
certain conditions. This fixes the problem by removing the
lines which write the queue files when exceptions occur.

Test included.

Fixes bug 1180884

Change-Id: If742a84cea1bd1f5abf99fb0e3cbd1e0c1623171
Merge "Fix for unencrypted uris in scrubber queue files"