Database.php: fix CodeException

extension/Classes/Core/Database/Database.php

@@ -972,7 +972,7 @@ class Database {
         if (false === $executed) {
             $errorMsg[ERROR_MESSAGE_TO_USER] = 'SQL Error.';
             $errorMsg[ERROR_MESSAGE_TO_DEVELOPER] = "Error playing multi query: " . $sqlStatements;
-            throw new \CodeException($errorMsg, ERROR_PLAY_SQL_MULTIQUERY);
+            throw new \CodeException(json_encode($errorMsg), ERROR_PLAY_SQL_MULTIQUERY);
         }
 
         // discard all results: this is important - if missed, following calls on $mysqli will fail.