Fixing the PYTHONHASHSEED bug with our unittests

Switching from HTTPInternalServerError to HTTPServerError
as Pecan seems to be returning HTTPServerError instead.
For some reason the assertion only fails with specific
PYTHONHASHSEED's. As a result, I'm just making sure we
assert against the returned exception to correct the
issue for the moment.

Change-Id: Iad15fa17fc2c4d5c3642462df25e702aaff4801f
Partial-bug: #1348818
Merge "Fixing the PYTHONHASHSEED bug with our unittests"