Fix other clippy lints

Author: yoshuawuyts

src/headers/header_name.rs

@@ -135,6 +135,7 @@ mod tests {
     use super::*;
 
     #[test]
+    #[allow(clippy::eq_op)]
     fn test_header_name_static_non_static() {
         let static_header = HeaderName::from_lowercase_str("hello");
         let non_static_header = HeaderName::from_str("hello").unwrap();

src/other/retry_after.rs

@@ -109,9 +109,9 @@ impl RetryAfter {
     }
 }
 
-impl Into<SystemTime> for RetryAfter {
-    fn into(self) -> SystemTime {
-        match self.inner {
+impl From<RetryAfter> for SystemTime {
+    fn from(retry_after: RetryAfter) -> Self {
+        match retry_after.inner {
             RetryDirective::Duration(dur) => SystemTime::now() + dur,
             RetryDirective::SystemTime(at) => at,
         }