Fix unintegration of other PRs upon PR closure

Before an early PR closure (or new commit) had the power to unintegrate PRs in
the train, regardless if this PR was integrated or not!  The unintegration of
later PRs should only happen when the PR being closed has been integrated and
thus is the base for these following PRs.

src/Logic.hs

@@ -380,9 +380,10 @@ handlePullRequestClosed closingReason pr state = do
   -- actually delete the pull request
   pure . Pr.deletePullRequest pr
        $ case Pr.lookupPullRequest pr state of
-         Just (Pr.PullRequest{Pr.integrationStatus = Promoted}) -> state
-         -- we unintegrate PRs after it if it has not been promoted to master
-         _ -> unintegrateAfter pr $ state
+         -- we unintegrate PRs after if it has been integrated without promotion
+         -- as everything that was built on top of it needs to be rebuilt
+         Just (Pr.PullRequest{Pr.integrationStatus = Integrated _ _}) -> unintegrateAfter pr state
+         _ -> state
 
 handlePullRequestEdited :: PullRequestId -> Text -> BaseBranch -> ProjectState -> Action ProjectState
 handlePullRequestEdited prId newTitle newBaseBranch state =