Prefer import type when importing types

ts/components/CallingLobbyJoinButton.tsx

@@ -1,7 +1,8 @@
 // Copyright 2021 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
-import React, { FunctionComponent, ReactChild, useState } from 'react';
+import type { FunctionComponent, ReactChild } from 'react';
+import React, { useState } from 'react';
 import { noop } from 'lodash';
 
 import type { LocalizerType } from '../types/Util';