test: preemptively disable sparse-revlog for some of test-upgrade-repo

Some part of this test assumes sparse-revlog is off. We enforce it explicitly.

Differential Revision: https://phab.mercurial-scm.org/D5344

tests/test-upgrade-repo.t

@@ -330,7 +330,7 b' Upgrading a repository to generaldelta w'
   $ touch f2
   $ hg -q commit -A -m 'add f2'
 
-  $ hg debugupgraderepo --run
+  $ hg debugupgraderepo --run --config format.sparse-revlog=false
   upgrade will perform the following actions:
   
   requirements
@@ -720,7 +720,7 b' repository config is taken in account'
 Check upgrading a sparse-revlog repository
 ---------------------------------------
 
-  $ hg init sparserevlogrepo
+  $ hg init sparserevlogrepo --config format.sparse-revlog=no
   $ cd sparserevlogrepo
   $ touch foo
   $ hg add foo