fix(Dockerfile) add ca-certificates

[deadc]

Context

Fix error with oauth2.googleapis.com ssl

...
2022/11/27 04:27:04 DEBUG : fs cache: renaming cache item "/data/" to be canonical "/data"
2022/11/27 04:27:04 DEBUG : Creating backend with remote "remote:/vaultwarden-sync/"
2022/11/27 04:27:04 DEBUG : remote: Loaded invalid token from config file - ignoring
2022/11/27 04:27:04 DEBUG : remote: Token refresh failed try 1/5: Post "https://oauth2.googleapis.com/token": x509: certificate signed by unknown authority
2022/11/27 04:27:05 DEBUG : remote: Loaded invalid token from config file - ignoring
2022/11/27 04:27:05 DEBUG : remote: Token refresh failed try 2/5: Post "https://oauth2.googleapis.com/token": x509: certificate signed by unknown authority
...

[blackandred]

Looks fine, builds and runs.

[blackandred]

LGTM

[blackandred]

Thanks for the contribution 😃