UCP failes to start due to small RSA Key

When installing UCP on Debian Buster the start of UCP node fails:

2019-09-07 13:36 +00:00: Starting FreePBX...OUT > 2019-09-07 13:36 +00:00: FreePBX is Ready!
Asterisk version is: 16.5.1
OUT >
==> /var/log/asterisk/ucp_err.log <==
2019-09-07 13:36 +00:00: Error: error:140AB18F:SSL routines:SSL_CTX_use_certificate:ee key too small
    at Object.createSecureContext (_tls_common.js:137:17)
    at Server.setSecureContext (_tls_wrap.js:1080:27)
    at Server (_tls_wrap.js:960:8)
    at new Server (https.js:61:14)
    at Object.createServer (https.js:84:10)
    at Server (/var/www/html/admin/modules/ucp/node/lib/server.js:98:19)
    at EventEmitter.<anonymous> (/var/www/html/admin/modules/ucp/node/index.js:19:49)
    at EventEmitter.emit (events.js:193:13)
    at EventEmitter.emit (domain.js:481:20)
    at /var/www/html/admin/modules/ucp/node/lib/freepbx.js:44:11

This is caused by the requirement of Debian Buster that all RSA keys have to be 2048 bits (or longer).