bug(chinese, japanese, korean): CJK keyboards do not work on mobile devices

[mcdurdin]

Reported as a bug by @jacobbowdoin in keymanapp/keyman#1754.

Chinese and Japanese character suggestions don't show on mobile.

Steps to reproduce the behavior:

1. On Chrome's mobile emulator, go to https://keymanweb.com/?_ga=2.108790466.192781627.1556551802-690591968.1556148767#cmn,Keyboard_chinese or https://keymanweb.com/?_ga=2.130287439.192781627.1556551802-690591968.1556148767#ja,Keyboard_japanese
2. Click on the text input
3. Type anything
4. For each keystroke receive error:

Uncaught TypeError: Cannot set property 'innerHTML' of null
    at Keyboard_chinese.C (chinese-1.0.js:1)
    at Keyboard_chinese.show (chinese-1.0.js:1)
    at Keyboard_chinese.showCandidates (chinese-1.0.js:1)

When I type, I expect to receive character suggestions to click on.