Setting codimd on heroku buttons → self signed certificate error

I just tried deploy codimd using `https://elements.heroku.com/buttons/hackmdio/codimd`.
I dont touch any option input and put deploy button.
Build Succeed and access then,,,

here is the log
```bash
2021-10-13T04:11:26.631231+00:00 heroku[web.1]: Starting process with command `./bin/heroku_start.sh`
2021-10-13T04:11:27.957025+00:00 app[web.1]:
2021-10-13T04:11:27.957041+00:00 app[web.1]: > codimd@2.4.1 start /app
2021-10-13T04:11:27.957042+00:00 app[web.1]: > sequelize db:migrate && node app.js
2021-10-13T04:11:27.957042+00:00 app[web.1]:
2021-10-13T04:11:28.166867+00:00 app[web.1]: 2021-10-13T04:11:28.165Z warn: Neither 'domain' nor 'CMD_DOMAIN' is configured. This can cause issues with various components.
2021-10-13T04:11:28.166869+00:00 app[web.1]: Hint: Make sure 'protocolUseSSL' and 'urlAddPort' or 'CMD_PROTOCOL_USESSL' and 'CMD_URL_ADDPORT' are configured properly.
2021-10-13T04:11:28.168435+00:00 app[web.1]: 2021-10-13T04:11:28.168Z warn: Session secret not set. Using random generated one. Please set `sessionSecret` in your config.js file. All users will be logged out.
2021-10-13T04:11:28.411757+00:00 app[web.1]:
2021-10-13T04:11:28.412145+00:00 app[web.1]: Sequelize CLI [Node: 12.22.7, CLI: 5.5.1, ORM: 5.21.3]
2021-10-13T04:11:28.412175+00:00 app[web.1]:
2021-10-13T04:11:28.420799+00:00 app[web.1]: Parsed url postgres://uoeiorovcelpyn:*****@ec2-3-222-24-200.compute-1.amazonaws.com:5432/df7blnahq1lghm
2021-10-13T04:11:28.508279+00:00 app[web.1]:
2021-10-13T04:11:28.508445+00:00 app[web.1]: ERROR: self signed certificate
2021-10-13T04:11:28.508488+00:00 app[web.1]:
2021-10-13T04:11:28.516168+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2021-10-13T04:11:28.516260+00:00 app[web.1]: npm ERR! errno 1
2021-10-13T04:11:28.519695+00:00 app[web.1]: npm ERR! codimd@2.4.1 start: `sequelize db:migrate && node app.js`
2021-10-13T04:11:28.519736+00:00 app[web.1]: npm ERR! Exit status 1
2021-10-13T04:11:28.519792+00:00 app[web.1]: npm ERR!
2021-10-13T04:11:28.519834+00:00 app[web.1]: npm ERR! Failed at the codimd@2.4.1 start script.
2021-10-13T04:11:28.519882+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2021-10-13T04:11:28.524712+00:00 app[web.1]:
2021-10-13T04:11:28.524798+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2021-10-13T04:11:28.524839+00:00 app[web.1]: npm ERR! /app/.npm/_logs/2021-10-13T04_11_28_520Z-debug.log
2021-10-13T04:11:28.641725+00:00 heroku[web.1]: Process exited with status 1
2021-10-13T04:11:28.742234+00:00 heroku[web.1]: State changed from starting to crashed
```