BUG-8494: do not attempt to reconnect ReconnectingClientConnection

If we are in reconnect state, we should never attempt to initiate
reconnection, as that would leave us without the timer running --
which is a problem since we need to be timing out requests which
are queued even as we are attempting to reconnect to the backend.

Change-Id: Ic955a2e5b743617c26cc72815df94d0c4584704c
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit 584be7bf6b41f2f8b01dd718aba8d3b6cf7426ef)