Ignore custom tooltip if its text is empty in signals tab

editor/connections_dialog.cpp

@@ -907,7 +907,7 @@ ConnectDialog::~ConnectDialog() {
 
 Control *ConnectionsDockTree::make_custom_tooltip(const String &p_text) const {
 	// If it's not a doc tooltip, fallback to the default one.
-	if (p_text.contains("::")) {
+	if (p_text.is_empty() || p_text.contains("::")) {
 		return nullptr;
 	}