[glom/gtkmm4v3: 17/21] gtkmm4: DialogExistingOrNew: const correction.

[Murray Cumming <murrayc src gnome org>]

commit cb0448cfabc84c7baf35675d4c525a4ce99b193d
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Mar 14 10:10:40 2017 +0100

    gtkmm4: DialogExistingOrNew: const correction.
    
    The gtkmm4 TreeModel::iterator is now more strict.

 glom/dialog_existing_or_new.cc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glom/dialog_existing_or_new.cc b/glom/dialog_existing_or_new.cc
index 2c04e9b..5d8ece3 100644
--- a/glom/dialog_existing_or_new.cc
+++ b/glom/dialog_existing_or_new.cc
@@ -736,7 +736,7 @@ void Dialog_ExistingOrNew::on_service_found(const Glib::ustring& name, EpcServic
 void Dialog_ExistingOrNew::on_service_removed(const Glib::ustring& name, const Glib::ustring& /* type */)
 {
   // Find the entry with the given name
-  const auto children = m_iter_existing_network->children();
+  auto children = m_iter_existing_network->children();
   for(auto iter = children.begin(); iter != children.end(); ++ iter)
   {
     if((*iter)[m_existing_columns.m_col_service_name] == name)