Fixes#2628
A sanity check is performed when calculating the uptime of a monitor on
status page. If it is greater than 100%, we just show 100%. This hasn't
been implemented on the dashboard at the request of @louislam due to
concerns it would make debugging more difficult in future if changes
were made to the uptime calculation.
Signed-off-by: Matthew Nickson <mnickson@sidingsmedia.com>