When copying message properties from the core message to the OpenWire
message we intentially omit any properties starting with `_AMQ` and
`__HDR_`. However, we were effectively negating that logic because we
copied the marshalled properties directly to the message without any
filtering. Now that we no longer copy the marshalled properties directly
to the message the test breaks because it expects properties starting
with `__HDR_`. This commit fixes the test by removing those
expectations. The test is still valid because the message is still
receieved rather than being swallowed due to an exception (which was the
original problem).