tests: don't log manifest-file in test-strip-cross.t
I'm confident that the file is there only to help produce a certain
manifest log; there is nothing special about the file's filelog
itself. (And there already is a `hg debugindex --manifest` call higher
up in the file that shows the crossed linkrevs.)
Differential Revision: https://phab.mercurial-scm.org/D6791
$ hg init
$ echo a > a
$ hg ci -Am t
adding a
$ hg mv a b
$ hg ci -Am t1
$ hg debugrename b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
$ hg mv b a
$ hg ci -Am t2
$ hg debugrename a
a renamed from b:37d9b5d994eab34eda9c16b195ace52c7b129980
$ hg debugrename --rev 1 b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3