Can't create compreface account

**Describe the bug**

Installed Compreface on Debian 11. Went to UI URL. tried to create account. See this:


**To Reproduce**

Steps to reproduce the behavior:

**Expected behavior**

Should be able to create an account
**Screenshots**

If applicable, add screenshots to help explain your problem.

**Desktop (please complete the following information):**

- OS: [e.g. iOS]
- Browser [e.g. chrome, safari]
- Version [e.g. 22]

**Logs**

Run those commands and attach result to the ticket:

`docker ps`

`docker-compose logs`

compreface-core | Python main interpreter initialized at 0x560fcdff1c90
compreface-core | python threads support enabled
compreface-core | your server socket listen backlog is limited to 100 connections
compreface-core | your mercy for graceful operations on workers is 60 seconds
compreface-core | mapped 218712 bytes (213 KB) for 2 cores
compreface-core | *** Operational MODE: preforking ***
compreface-admin | 2023-02-14 16:40:02.698 INFO 7 --- [ main] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.PostgreSQL10Dialect
compreface-admin | 2023-02-14 16:40:05.252 INFO 7 --- [ main] Hibernate Types : This framework is proudly powered by:
compreface-admin |
compreface-admin | >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
compreface-admin | _ _ _ _
compreface-admin | | | | | (_) | |
compreface-admin | | |__| |_ _ _ __ ___ _ __ ___ _ ___| |_ ___ _ __ ___ ___
compreface-admin | | __ | | | | '_ \ / _ \ '__/ __| / __| __/ _ \ '_ \ / __/ _ \
compreface-admin | | | | | |_| | |_) | __/ | \__ \ \__ \ || __/ | | | (_| __/
compreface-admin | |_| |_|\__, | .__/ \___|_| |___/_|___/\__\___|_| |_|\___\___|
compreface-admin | __/ | |
compreface-admin | |___/|_|
compreface-admin |
compreface-admin | At Hypersistence, we only build amazing tools, like Hibernate Types, Flexy Pool, or Hypersistence Optimizer.
compreface-admin |
compreface-admin | What if there were a tool that could automatically detect JPA and Hibernate performance issues?
compreface-admin |
compreface-admin | Hypersistence Optimizer is that tool! For more details, go to:
compreface-admin |
compreface-admin | https://vladmihalcea.com/hypersistence-optimizer/
compreface-admin | <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
compreface-admin |
compreface-api | 2023-02-14 16:40:15.373 INFO 7 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
compreface-ui | 2023/02/14 16:40:21 [error] 27#27: *19 connect() failed (111: Connection refused) while connecting to upstream, client: 192.168.86.53, server: ui, request: "POST /admin/user/register HTTP/1.1", upstream: "http://172.25.0.5:8080/user/register", host: "192.168.86.47:8000", referrer: "http://192.168.86.47:8000/sign-up"
compreface-ui | 192.168.86.53 - - [14/Feb/2023:16:40:21 +0000] "POST /admin/user/register HTTP/1.1" 502 552 "http://192.168.86.47:8000/sign-up" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36"
compreface-api | 2023-02-14 16:40:22.275 INFO 7 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
compreface-api | 2023-02-14 16:40:26.602 INFO 7 --- [ main] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.PostgreSQL10Dialect
compreface-core exited with code 0
compreface-core | Python main interpreter initialized at 0x55d36353cc90
compreface-core | python threads support enabled
compreface-core | your server socket listen backlog is limited to 100 connections
compreface-core | your mercy for graceful operations on workers is 60 seconds
compreface-core | mapped 218712 bytes (213 KB) for 2 cores
compreface-core | *** Operational MODE: preforking ***

**Additional context**

Add any other context about the problem here.

Start with the supplied docker-compose logs, especially the compreface-ui error for POST /admin/user/register and the startup logs for compreface-admin and compreface-api. Reproduce the sign-up request and determine why the upstream connection is refused. Done means account creation succeeds without a 502 response and the relevant service logs show a healthy request path.

Written by the indexing model from the issue text.