Fix #450: jobmaker may not be ready for a long time after restarting.

Fixed:

• #450: jobmaker may not be ready for a long time after restarting.
• #432: getblocktemplatelight is not called for BCH gbtmaker when receiving ZMQ notification
• #448: too large share_stale number in the database.
• #405: uninitialized variable modifyHoursFlag_ in statshttpd.