tests: actually check that HGDEMANDIMPORT=disable disables demandimport...
tests: actually check that HGDEMANDIMPORT=disable disables demandimport
At the point in the test where we were checking that the 'node' got
eagerly loaded, it had already been loaded (via the pvec module), so
our check wasn't doing anything (i.e. the test would pass even if you
removed the line that set HGDEMANDIMPORT=disable). Let's move this
test earlier so it tests what it was meant to test.
Differential Revision:
https://phab.mercurial-scm.org/D2286
