Add support to work with PyQt5 5.14
If it is possible, please add support to work with PyQt5 5.14 (Chromium 77) - to avoid this error on Ubuntu 20.04:
$ deemix-pyweb
Server not started
INFO:deemix:Linux-5.4.0-47-generic-x86_64-with-glibc2.29 - Python 3.8.2, deemix 2.0.4
Starting server at http://127.0.0.1:6595
js: Uncaught SyntaxError: Unexpected token '?'
Shutting down server