Disable editing of the description of the connections in the connection ListView.

Also replace the integer literals defining the columns for enum to make more readable.

pglab/ConnectionListModel.h

@@ -18,6 +18,18 @@ class ConnectionList;
 class ConnectionListModel : public QAbstractListModel {
 	Q_OBJECT
 public:
+	enum Columns {
+		Description,
+		Name,
+		Host,
+		Port,
+		User,
+		Password,
+		DbName,
+
+		ColCount
+	};
+
 	ConnectionListModel(ConnectionList *conns, QObject *parent);
 	ConnectionListModel(const ConnectionListModel&) = delete;
 	~ConnectionListModel() override;