Merge pull request #1 from shamimmoeen/master

Fix wrong error message

Author: arkadiusjonczek

src/DeepL.php

@@ -204,7 +204,7 @@ protected function checkLanguages($sourceLanguage, $destinationLanguage)
         $destinationLanguage = strtoupper($destinationLanguage);
 
         if (!in_array($destinationLanguage, $this->destinationLanguages)) {
-            throw new DeepLException(sprintf('The language "%s" is not supported as destination language.', $sourceLanguage));
+            throw new DeepLException(sprintf('The language "%s" is not supported as destination language.', $destinationLanguage));
         }
 
         return true;
@@ -318,4 +318,4 @@ protected function request($url, $body)
 
         return $translationsArray;
     }
-}
+}