test: use bundle2 for exchange in test-obsolete

The bundle2 version of obsmarkers exchange is more informative. Switching to
bundle2 by default will change the output of this tests. To reduce the noise
when switching bundle2 to the default protocol, we migrate this tests early.

tests/test-obsolete.t

@@ -4,6 +4,10 b''
   > publish=false
   > [ui]
   > logtemplate="{rev}:{node|short} ({phase}) [{tags} {bookmarks}] {desc|firstline}\n"
+  > [experimental]
+  > # drop me once bundle2 is the default,
+  > # added to get test change early.
+  > bundle2-exp = True
   > EOF
   $ mkcommit() {
   >    echo "$1" > "$1"
@@ -307,6 +311,7 b' Try to pull markers'
   adding manifests
   adding file changes
   added 4 changesets with 4 changes to 4 files (+1 heads)
+  5 new obsolescence markers
   (run 'hg heads' to see heads, 'hg merge' to merge)
   $ hg debugobsolete
   1337133713371337133713371337133713371337 5601fb93a350734d935195fee37f4054c529ff39 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
@@ -348,6 +353,7 b' Try to push markers'
   adding manifests
   adding file changes
   added 4 changesets with 4 changes to 4 files (+1 heads)
+  5 new obsolescence markers
   $ hg -R tmpd debugobsolete | sort
   1337133713371337133713371337133713371337 5601fb93a350734d935195fee37f4054c529ff39 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
   245bde4270cd1072a27757984f9cda8ba26f08ca cdbce2fbb16313928851e97e0d85413f3f7eb77f C (Thu Jan 01 00:00:01 1970 -0002) {'user': 'test'}
@@ -410,6 +416,7 b' On pull'
   adding manifests
   adding file changes
   added 4 changesets with 4 changes to 4 files (+1 heads)
+  5 new obsolescence markers
   (run 'hg heads' to see heads, 'hg merge' to merge)
   $ hg debugobsolete
   1339133913391339133913391339133913391339 ca819180edb99ed25ceafb3e9584ac287e240b00 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
@@ -426,6 +433,7 b' On push'
   pushing to ../tmpc
   searching for changes
   no changes found
+  1 new obsolescence markers
   [1]
   $ hg -R ../tmpc debugobsolete
   1337133713371337133713371337133713371337 5601fb93a350734d935195fee37f4054c529ff39 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
@@ -508,6 +516,7 b" Don't try to push extinct changeset"
   adding manifests
   adding file changes
   added 6 changesets with 6 changes to 6 files (+1 heads)
+  7 new obsolescence markers
 
 no warning displayed
 
@@ -547,6 +556,7 b' Do not warn about new head when the new '
   adding manifests
   adding file changes
   added 1 changesets with 1 changes to 1 files (+1 heads)
+  1 new obsolescence markers
 
 test relevance computation
 ---------------------------------------
@@ -764,6 +774,7 b' This test issue 3814'
   adding manifests
   adding file changes
   added 1 changesets with 1 changes to 1 files
+  2 new obsolescence markers
   $ hg out ../repo-issue3814
   comparing with ../repo-issue3814
   searching for changes