make test-mq-qdelete work reliably (issue1180)

if after a and b has been applied, their hash starts with c, then the test
would fail (because there would be a rev c which would be seen as "applied")
so probability of failure would be 2*1/16.

tests/test-mq-qdelete

@@ -9,9 +9,9 b' cd a'
 echo 'base' > base
 hg ci -Ambase -d '1 0'
 
-hg qnew a
-hg qnew b
-hg qnew c
+hg qnew -d '1 0' a
+hg qnew -d '1 0' b
+hg qnew -d '1 0' c
 
 hg qdel
 
@@ -41,14 +41,14 b' hg init b'
 cd b
 
 echo 'base' > base
-hg ci -Ambase
+hg ci -Ambase -d '1 0'
 
 hg qfinish
 hg qfinish -a
 
-hg qnew a
-hg qnew b
-hg qnew c
+hg qnew -d '1 0' a
+hg qnew -d '1 0' b
+hg qnew c # XXX fails to apply by /usr/bin/patch if we put a date
 
 hg qfinish 0
 hg qfinish b