[smuxi/stable] Frontend-GNOME: fix NRE when closing chats during reconnect to the remote engine (closes: #1091)

[Mirco M. M. Bauer <mmmbauer src gnome org>]

commit cf39e9966f29806cdce4882fcb45d78ea8c8699e
Author: Mirco Bauer <meebey meebey net>
Date:   Wed Jun 29 22:33:35 2016 +0200

    Frontend-GNOME: fix NRE when closing chats during reconnect to the remote engine (closes: #1091)

 src/Frontend-GNOME/Views/MenuWidget.cs |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/Frontend-GNOME/Views/MenuWidget.cs b/src/Frontend-GNOME/Views/MenuWidget.cs
index 829ebab..29e17e4 100644
--- a/src/Frontend-GNOME/Views/MenuWidget.cs
+++ b/src/Frontend-GNOME/Views/MenuWidget.cs
@@ -364,7 +364,9 @@ namespace Smuxi.Frontend.Gnome
             Trace.Call(sender, e);
             
             try {
-                ChatViewManager.CurrentChatView.Close();
+                if (ChatViewManager.CurrentChatView != null) {
+                    ChatViewManager.CurrentChatView.Close();
+                }
                 if (Frontend.IsMacOSX && ChatViewManager.Chats.Count == 1) {
                     ChatViewManager.Minimize();
                 }