Don't reset tested YubiKeys in key::filter_connected

This method only connects to YubiKeys in order to confirm it can do so
(i.e. as a side-effect). We therefore want to explicitly disconnect
without resetting the YubiKeys, to avoid clearing PIN caches.

src/key.rs

@@ -48,7 +48,13 @@ pub(crate) fn filter_connected(reader: &Reader) -> bool {
             );
             false
         }
-        _ => true,
+        Err(_) => true,
+        Ok(yubikey) => {
+            // We only connected as a side-effect of confirming that we can connect, so
+            // avoid resetting the YubiKey.
+            disconnect_without_reset(yubikey);
+            true
+        }
     }
 }