Disable combination of stacked charts and log scale
This combination is confusing, as in this example: https://stats.nic.cz/stats/registry_operations/?rd=2013-08-14&dr=1m&tp=i-1m&ss=0&ds=log&da=chart
This combination is confusing, as in this example: https://stats.nic.cz/stats/registry_operations/?rd=2013-08-14&dr=1m&tp=i-1m&ss=0&ds=log&da=chart