add image/vnd.dwg signature (#1803)

* Update fileinput.js

add image/vnd.dwg

* Update fileinput.js

js/fileinput.js

@@ -459,6 +459,8 @@
                     return 'image/tiff';
                 case '52494646':
                     return 'image/webp';
+                case '41433130':
+                    return 'image/vnd.dwg';
                 case '66747970':
                     return 'video/3gp';
                 case '4f676753':
@@ -6571,4 +6573,4 @@
             $input.fileinput();
         }
     });
-}));
+}));