Increase HTTP signature expiration time to one day (fixes #46)

[ghost]

Are you sure it's working as intended?

I still get regular "Signature is expired" logs. Both instances are running on 0.18.0 and therefore, should use this PR already.

lemmy-proxy     | 172.16.255.2 - - [23/Jun/2023:21:27:35 +0000] "POST /inbox HTTP/1.1" 400 45 "-" "Lemmy/0.18.0; +https://lemmy.ml"
lemmy           | 2023-06-23T21:27:35.578869Z  WARN lemmy_server::root_span_builder: Other errors which are not explicitly handled
lemmy           |    0: lemmy_server::root_span_builder::HTTP request
lemmy           |            with http.method=POST http.scheme="https" http.host=lemmy.example.com http.target=/inbox otel.kind="server" request_id=91ea25d3-2d7a-4b93-97e4-c41acc4855a8
lemmy           |              at src/root_span_builder.rs:16
lemmy           | LemmyError { message: None, inner: Other errors which are not explicitly handled
lemmy           |
lemmy           | Caused by:
lemmy           |     Http Signature is expired, checked Date header, checked at Fri, 23 Jun 2023 21:27:35 GMT, expired at Fri, 23 Jun 2023 21:26:31 GMT, context: SpanTrace [{ target: "lemmy_server::root_span_builder", name: "HTTP request", fields: "http.method=POST http.scheme=\"https\" http.host=lemmy.example.com http.target=/inbox otel.kind=\"server\" request_id=91ea25d3-2d7a-4b93-97e4-c41acc4855a8", file: "src/root_span_builder.rs", line: 16 }] }

[Nutomic]

Youre right there is something going wrong.