download: Fix up snafu when reqwest backend is disabled

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

Author: kinnison

download/src/lib.rs

@@ -433,13 +433,15 @@ pub mod curl {
 pub mod reqwest_be {
 
     use super::Event;
+    use super::TlsBackend;
     use crate::errors::*;
     use url::Url;
 
     pub fn download(
         _url: &Url,
         _resume_from: u64,
         _callback: &dyn Fn(Event<'_>) -> Result<()>,
+        _tls: TlsBackend,
     ) -> Result<()> {
         Err(ErrorKind::BackendUnavailable("reqwest").into())
     }