QUIC: simplified setting close timer when closing connection. Previously, the timer was never reset due to an explicit check. The check was added in 36b59521a41c as part of connection close simplification. The reason was to retain the earliest timeout. However, the timeouts are all the same while QUIC handshake is in progress and resetting the timer for the same value has no performance implications. After handshake completion there's only application level. The change removes the check.