tests: remove references to bundle2-exp config option

This option was deleted a while ago. We don't even alias it in
core.

Differential Revision: https://phab.mercurial-scm.org/D2198

tests/narrow-library.sh

@@ -4,6 +4,5 b' narrow='
 [ui]
 ssh=python "$TESTDIR/dummyssh"
 [experimental]
-bundle2-exp = True
 changegroup3 = True
 EOF

tests/test-pushvars.t

@@ -11,8 +11,6 b' Setup'
   $ cat >> $HGRCPATH << EOF
   > [hooks]
   > pretxnchangegroup = sh $TESTTMP/pretxnchangegroup.sh
-  > [experimental]
-  > bundle2-exp = true
   > EOF
 
   $ hg init repo