Fix issue #5029 (#5041)
Fix issue #5029 (#5041)

- infinite loop in generating time axis, due to insufficient bounds checking.
touletan/Chart.js,supernovel/Chart.js,supernovel/Chart.js,simonbrunel/Chart.js,jtcorbett/Chart.js,simonbrunel/Chart.js,touletan/Chart.js,touletan/Chart.js,touletan/Chart.js,chartjs/Chart.js,chartjs/Chart.js,chartjs/Chart.js,jtcorbett/Chart.js,nnnick/Chart.js,chartjs/Chart.js