Form: does not show 'no associated handlers' error if the form is not…

… submitted by the button

https://forum.nette.org/cs/34670-user-warning-form-was-submitted-but-there-are-no-associated-handlers#p226590

src/Forms/Form.php

@@ -490,7 +490,7 @@ public function fireEvents(): void
 			$this->validate();
 		}
 
-		$handled = count($this->onSuccess ?? []) || count($this->onSubmit ?? []);
+		$handled = count($this->onSuccess ?? []) || count($this->onSubmit ?? []) || $this->submittedBy === true;
 
 		if ($this->submittedBy instanceof Controls\SubmitButton) {
 			$handled = $handled || count($this->submittedBy->onClick ?? []);