Fix #2402 - Add Idempotency-Key header to PostStatusService that prevents (#2419)

duplicates. Web UI regenerates UUID for that header every time the compose
form is changed or successfully submitted

Also, fix Farsi i18n overwriting the English one

app/assets/javascripts/components/actions/compose.jsx

@@ -85,6 +85,10 @@ export function submitCompose() {
       sensitive: getState().getIn(['compose', 'sensitive']),
       spoiler_text: getState().getIn(['compose', 'spoiler_text'], ''),
       visibility: getState().getIn(['compose', 'privacy'])
+    }, {
+      headers: {
+        'Idempotency-Key': getState().getIn(['compose', 'idempotencyKey'])
+      }
     }).then(function (response) {
       dispatch(submitComposeSuccess({ ...response.data }));