Pass through error message to VE if Parsoid is unreachable.

The Status is marked as 'ok' if it completes with errors. We need
to check for the Status is 'good' as well, and if not we can
pass through the error.

MWHttpRequest only sets fatal errors so it can be assumed that if
the Status is not 'good' then there is one error in the error array.

Bug: 45916
Change-Id: Icb2d0253faaf4e00a9a1fe3091458b914e5b7579
Merge "Pass through error message to VE if Parsoid is unreachable."