Add is_object check in IssueService::addAttachments

Author: say1hello

src/Issue/IssueService.php

@@ -139,6 +139,11 @@ public function addAttachments($issueIdOrKey, $filePathArray)
                     $ret, new \ArrayObject(), '\JiraRestApi\Issue\Attachment'
                     )
                 );
+            } elseif (is_object($ret)) {
+                array_push($resArr, $this->json_mapper->map(
+                    $ret, new Attachment
+                    )
+                );
             }
         }