Don't show 'saved' on display name save error (#12600)

The save callback nees to throw on an error so the EditInPlace
component knows it's not been successful.

src/components/views/settings/UserProfileSettings.tsx

@@ -131,6 +131,7 @@ const UserProfileSettings: React.FC = () => {
             setInitialDisplayName(displayName);
         } catch (e) {
             setDisplayNameError(true);
+            throw e;
         }
     }, [displayName, client]);