* qubesos/pr/190:
Missed one test, adding default-user in assert for test test_621_qdb_vm_with_network in TC_90
replaced underscore by dash and update test accordingly
Updated assert content for test_620_qdb_standalone in TC_90_QubesVM
Added the default_user property from the Qube to the qubesdb so it is available when starting X. This is the 1st part of a fix for issue https://github.com/QubesOS/qubes-issues/issues/2372