Fix rewrite of User-Agent header

[vbrvk]

Motivation

For now passed User-Agent header is rewritten to foundry/version, but it should not

Solution

Fix header existence check condition (HeaderName is lowercased and do not contains :)

[grandizzy]

@vbrvk thank you! would it be possible to have a unit test to prevent regressions, in this way could also better understand the issue and solution too

[vbrvk]

@grandizzy actually I was thinking about tests but it is not possible to retrieve headers of request without firing it, so local server start required. I thought it is overkill for such little thing.

You OK with such approach or you suggesting more simple test?

    #[tokio::test]
    async fn test_headers() {
        let transport = RuntimeTransportBuilder::new(Url::parse("127.0.0.1").unwrap())
            .with_headers(vec!["User-Agent: test-agent".to_string()])
            .build();

        let inner = transport.connect_http().await.unwrap();

        match inner {
            InnerTransport::Http(http) => {
                let client = http.client();

                let req = client.get("/").build().unwrap();
                
                let actual_headers = req.headers();
                
                // aseert here
            }
            _ => unreachable!(),
        }
    }

[grandizzy]

@grandizzy actually I was thinking about tests but it is not possible to retrieve headers of request without firing it, so local server start required. I thought it is overkill for such little thing.

You OK with such approach or you suggesting more simple test?

    #[tokio::test]
    async fn test_headers() {
        let transport = RuntimeTransportBuilder::new(Url::parse("127.0.0.1").unwrap())
            .with_headers(vec!["User-Agent: test-agent".to_string()])
            .build();

        let inner = transport.connect_http().await.unwrap();

        match inner {
            InnerTransport::Http(http) => {
                let client = http.client();

                let req = client.get("/").build().unwrap();
                
                let actual_headers = req.headers();
                
                // aseert here
            }
            _ => unreachable!(),
        }
    }

that would be better than nothing, though if we need to start an anvil instance and then call cast or forge against we have several examples as here

foundry/crates/cast/tests/cli/main.rs

Line 1760 in 00c944b

forgetest_async!(decode_traces_with_project_artifacts, |prj, cmd| {

[vbrvk]

@grandizzy added test

So if fix not present, then test fails with

called `Result::unwrap()` on an `Err` value: reqwest::Error { kind: Request, url: "http://127.0.0.1:1337/", source: hyper_util::client::legacy::Error(SendRequest, hyper::Error(IncompleteMessage)) }
thread 'provider::runtime_transport::tests::test_user_agent_header' panicked at crates/common/src/provider/runtime_transport.rs:350:13:
assertion `left == right` failed
  left: "foundry/0.3.0"
 right: "test-agent"

[DaniPopes]

LGTM, thanks!