persistent-nodemap: disable it unconditionally for test-ssh-proto-unbundle.t

This is not relevant for the test and this will avoid a lot of variations.

Differential Revision: https://phab.mercurial-scm.org/D10335

tests/test-ssh-proto-unbundle.t

@@ -1,3 +1,10 b''
+persistent-nodemap is not enabled by default. It is not relevant for this test so disable it.
+
+  $ cat << EOF >> $HGRCPATH
+  > [format]
+  > use-persistent-nodemap = no
+  > EOF
+
   $ cat > hgrc-sshv2 << EOF
   > %include $HGRCPATH
   > [experimental]