[Glitch] SUBMIT doesn't exist on XMLHttpRequest

Port ab3f23da91 to glitch-soc

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

app/javascript/flavours/glitch/actions/markers.js

@@ -55,7 +55,7 @@ export const synchronouslySubmitMarkers = () => (dispatch, getState) => {
     client.open('POST', '/api/v1/markers', false);
     client.setRequestHeader('Content-Type', 'application/json');
     client.setRequestHeader('Authorization', `Bearer ${accessToken}`);
-    client.SUBMIT(JSON.stringify(params));
+    client.send(JSON.stringify(params));
   } catch (e) {
     // Do not make the BeforeUnload handler error out
   }