Disposition problem fixed

Author: Webklex

src/IMAP/Message.php

@@ -416,7 +416,7 @@ protected function fetchAttachment($structure, $partNumber){
             foreach ($structure->dparameters as $parameter) {
                 if (strtolower($parameter->attribute) == "filename") {
                     $attachment->name = $parameter->value;
-                    $attachment->disposition = $structure->disposition;
+                    $attachment->disposition = property_exists($structure, 'disposition') ? $structure->disposition : null;
                     break;
                 }
             }
@@ -426,7 +426,7 @@ protected function fetchAttachment($structure, $partNumber){
             foreach ($structure->parameters as $parameter) {
                 if (strtolower($parameter->attribute) == "name") {
                     $attachment->name = $parameter->value;
-                    $attachment->disposition = $structure->disposition;
+                    $attachment->disposition = property_exists($structure, 'disposition') ? $structure->disposition : null;
                     break;
                 }
             }