Fix nginx map_hash building issues on Raspberry Pi

[D-VR]

When running this docker container on a raspberry pi, the proxy fails. This is due to the signal relay failing because nginx can't create a map_hash.

See error:

sudo docker logs f9e47397ba89
2024/08/25 16:42:23 [emerg] 1#1: could not build map_hash, you should increase map_hash_bucket_size: 32
nginx: [emerg] could not build map_hash, you should increase map_hash_bucket_size: 32
2024/08/25 16:42:26 [emerg] 1#1: could not build map_hash, you should increase map_hash_bucket_size: 32
nginx: [emerg] could not build map_hash, you should increase map_hash_bucket_size: 32

adding map_hash_bucket_size to the nginx config fixes this issue when running on a raspberry pi.

Please test this change on other systems to make sure it doesn't break them

[D-VR]

Feature Request:
another thing which may be useful is to provide a simple config file for <not so technical> users, if they want to make simple changes like changing the external ports (i.e. port 80->8080). Since those running the signal proxy from home systems may already be using those ports for other projects

[D-VR]

I have signed the CLA

[mhida923-web]

When