title: Am chart v4 Tooltip issue
body: <blockquote>
    <p>I am using XY chart for line chart in amchart v4 , I am phasing issue in tooltip, I have customize tooltip text as html , but when mouse hover one line show all line tooltip, I want only selected line tooltip not for all lines, please help  </p>
  </blockquote>
  
  <p>Following image describes the issue that I'm facing:</p>
  
  <p><img src="https://i.stack.imgur.com/FGeHN.png" alt="tooltip issue screen shot"></p>