[pan2] Cannot start after removing last news server

[Petr Kovář <pmkovar src gnome org>]

commit 9ad1e024b27a6ec5c6164d85d8d88700403944cf
Author: freepro <freepro ngs ru>
Date:   Sat Jul 2 21:57:40 2016 +0200

    Cannot start after removing last news server

 pan/gui/group-pane.cc |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/pan/gui/group-pane.cc b/pan/gui/group-pane.cc
index 21b1317..bb575e6 100644
--- a/pan/gui/group-pane.cc
+++ b/pan/gui/group-pane.cc
@@ -844,6 +844,10 @@ GroupPane :: read_group (const StringView& groupname)
     PanTreeStore * tree (PAN_TREE_STORE(gtk_tree_view_get_model(view)));
     GtkTreeIter iter;
     const MyRow* row = find_row (groupname);
+    if(!row)
+    {
+      return;
+    }
     iter = tree->get_iter (row);
     read_group(gtk_tree_model_get_path(gtk_tree_view_get_model(view), &iter));
 }