[geary] Actually fire Geary.Account::closed signal when closing accounts.

[Michael Gratton <mjog src gnome org>]

commit 01259104e1d6fa1e20fbbcc82cd520eba17f837d
Author: Michael James Gratton <mike vee net>
Date:   Mon Nov 20 19:51:03 2017 +1100

    Actually fire Geary.Account::closed signal when closing accounts.

 .../imap-engine/imap-engine-generic-account.vala   |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/engine/imap-engine/imap-engine-generic-account.vala 
b/src/engine/imap-engine/imap-engine-generic-account.vala
index 455d291..d8a54f4 100644
--- a/src/engine/imap-engine/imap-engine-generic-account.vala
+++ b/src/engine/imap-engine/imap-engine-generic-account.vala
@@ -226,7 +226,9 @@ private abstract class Geary.ImapEngine.GenericAccount : Geary.Account {
         folder_map.clear();
         local_only.clear();
         open = false;
-        
+
+        notify_closed();
+
         if (local_err != null)
             throw local_err;