git: rebase: refresh the repo state info ASAP

it used to wait for the full refresh to complete, which can be slow.
in particular it led to such unfortunate effects: clicking abort
in the error notification could say "no rebase in progress" because the
VFS refresh didn't force .git/ files to refresh yet.

plugins/git4idea/src/git4idea/rebase/GitRebaseProcess.java

@@ -139,6 +139,7 @@ public class GitRebaseProcess {
         }
 
         GitRebaseStatus rebaseStatus = rebaseSingleRoot(repository, customMode, getSuccessfulRepositories(statuses));
+        repository.update(); // make the repo state info actual ASAP
         statuses.put(repository, rebaseStatus);
         if (shouldBeRefreshed(rebaseStatus)) {
           toRefresh.add(repository);