verifier: fixup time range check

Signed-off-by: Andrew Pan <[email protected]>

src/verify/verifier.rs

@@ -160,7 +160,7 @@ impl AsyncVerifier {
             .not_after
             .to_unix_duration()
             .as_secs();
-        if !(not_before <= integrated_time && integrated_time <= not_after) {
+        if integrated_time < not_before || integrated_time > not_after {
             return Err(CertificateErrorKind::Expired)?;
         }
         debug!("data signed during validity period");