[Glitch] Fix controls for unchangeable properties on status edit not being disabled

Port 38845592c4 to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/features/compose/components/privacy_dropdown.js

@@ -27,6 +27,7 @@ class PrivacyDropdown extends React.PureComponent {
     onChange: PropTypes.func.isRequired,
     noDirect: PropTypes.bool,
     container: PropTypes.func,
+    disabled: PropTypes.bool,
     intl: PropTypes.object.isRequired,
   };