Fix: Code. get_fields_any() notice fixed.

Author: Glomberg

inc/cleantalk-common.php

@@ -970,20 +970,19 @@ function ct_get_fields_any($arr, $message=array(), $email = null, $nickname = ar
         }
     } unset($v);
 
-	//If top iteration, returns compiled name field. Example: "Nickname Firtsname Lastname".
+	//If top iteration, returns compiled name field. Example: "Nickname Firtsname Lastname".]
+	$nickname_str = '';
 	if($nickname_default && $prev_name === ''){
 		if(!empty($nickname)){
-			$nickname_str = '';
 			foreach($nickname as $value){
 				$nickname_str .= ($value ? $value." " : "");
 			}unset($value);
 		}
-		$nickname = $nickname_str;
 	}
 
     $return_param = array(
 		'email' 	=> $email,
-		'nickname' 	=> $nickname,
+		'nickname' 	=> $nickname_str ?: $nickname,
 		'subject' 	=> $subject,
 		'contact' 	=> $contact,
 		'message' 	=> $message