[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/containers/upload_container.js

@@ -5,6 +5,7 @@ import { submitCompose } from 'flavours/glitch/actions/compose';
 
 const mapStateToProps = (state, { id }) => ({
   media: state.getIn(['compose', 'media_attachments']).find(item => item.get('id') === id),
+  isEditingStatus: state.getIn(['compose', 'id']) !== null,
 });
 
 const mapDispatchToProps = dispatch => ({