build_tools/release.sh: relax assertion about changelog title

I'd like to move to a process where everything goes into master first,
and then flows downstream to any release branches (i.e. no merging
of Integration_* branches back into master).

The only thing we need to change for that is to add release notes for
patch releases eagerly on master.  That implies that we want to use
the actual version instead of ???.  (Only if something goes wrong
in the release process, we need to change this on both branches,
but that should happen too often.)

build_tools/release.sh

@@ -53,7 +53,7 @@ integration_branch=$(
 [ -n "$integration_branch" ] ||
     git merge-base --is-ancestor $remote/master HEAD
 
-sed -n 1p CHANGELOG.rst | grep -q '^fish .*(released ???)$'
+sed -n 1p CHANGELOG.rst | grep -q '^fish .*(released .*)$'
 sed -n 2p CHANGELOG.rst | grep -q '^===*$'
 
 changelog_title="fish $version (released $(date +'%B %d, %Y'))"