test_import: remove unnecessary assert
test_import: remove unnecessary assert

The git.need-apply property does not exist anymore, the test is passing
only because the default passed to get_property is True.

Signed-off-by: Paolo Bonzini <69d3ebcf5ee4e7f05a50dc23cd96655b730804b4@redhat.com>

patchew-project/patchew,patchew-project/patchew,patchew-project/patchew,patchew-project/patchew