Updated default language path (#1390)

* Updated default language path

* Calculated path instead of building string version

* Removed whitespace in function call

src/PHPMailer.php

@@ -1994,7 +1994,7 @@ class PHPMailer
         ];
         if (empty($lang_path)) {
             // Calculate an absolute path so it can work if CWD is not here
-            $lang_path = __DIR__ . DIRECTORY_SEPARATOR . 'language' . DIRECTORY_SEPARATOR;
+            $lang_path = dirname(__DIR__) . DIRECTORY_SEPARATOR . 'language' . DIRECTORY_SEPARATOR;
         }
         //Validate $langcode
         if (!preg_match('/^[a-z]{2}(?:_[a-zA-Z]{2})?$/', $langcode)) {