Steps to Reproduce

http://10.1.3.241:8084/zkchartsdemo/line_labels

Current Result

the indicators (Tokyo and London) in the chart are partially covered by the numbers

both happens in Chrome and Firefox; covers only Tokyo in Safari

Susan 12/26: same on FF

Expected Result

either hidden the labels in the chart or adjust the labels so it won't be covered

Debug Information

 caused by series-label module since highcharts 6.0.0 (enabled: true by default)

Workaround