Don't close the connection dialog when the validation failed.

Currently the connection dialog is closed when

 1. no method name is specified, or

 2. no script is attached and if the method name isn't a buildin.

That's really annoying.

editor/connections_dialog.cpp

@@ -127,6 +127,7 @@ void ConnectDialog::ok_pressed() {
 		}
 	}
 	emit_signal("connected");
+	hide();
 }
 
 void ConnectDialog::_cancel_pressed() {
@@ -280,6 +281,8 @@ bool ConnectDialog::is_editing() const {
  */
 void ConnectDialog::init(Connection c, bool bEdit) {
 
+	set_hide_on_ok(false);
+
 	source = static_cast<Node *>(c.source);
 	signal = c.signal;