[awc] Discrepancy about default headers in code and documentation

[cailloumajor]

Expected Behavior

awc behavior being consistent with its API documentation.

Current Behavior

awc does not set User-Agent header by default, despite the presence of the following method, and its documentation: https://github.com/actix/actix-web/blob/ea8bf361041b35aa281835540f1e8aba9679aceb/awc/src/builder.rs#L119-L124 Moreover, the default_headers attribute does not seem to be used anywhere but in this method.

Possible Solution

I need your opinion here, to know if the doc should be fixed, or if default User-Agent header should be implemented.

I would be happy to contribute on a fix.

Steps to Reproduce (for bugs)

Context

Your Environment

• Rust Version (I.e, output of rustc -V): 1.53.0
• awc Version: 2.0.3