fix recaptcha validate_user_signup hook

wp-content/plugins/wp-recaptcha-bp/recaptcha.php

@@ -252,7 +252,7 @@ class ReCAPTCHAPlugin extends WPPlugin
                 $_POST['g-recaptcha-response'] == '') {
                 $result['errors']->add('blank_captcha',
                     $this->options['no_response_error']);
-                return $result['errors'];
+                return $result;
             }
 
             if ($this->_reCaptchaLib == null) {