test-dispatch: stabilize the test When cwd is removed and `hg` is executed, some shells may run `getcwd` before forking and executing, some may not do it, some may print a different error message. The test should be shell-independent so let's just avoid checking the error message. Differential Revision: https://phab.mercurial-scm.org/D1282

pager.pager=p0 # $TESTTMP/sysrc:4
ui.editor=e1 # $TESTTMP/userrc:2

pager.pager=p2 # $PAGER
ui.editor=e1 # $TESTTMP/userrc:2