Setting title times to negative values acts like /time ... clear

The bug

When you set the the title times all to negative value it acts like the /title ... clear command.

Expected behavior

The /title command should not allow negative time values.

How to reproduce

1. Set a subtitle

   /title @a subtitle ["Subtitle"]
   

2. Set all title times to negative values

   /title @a times -1 -1 -1
   

3. Display a title

   /title @a title ["Title"]
   

   → You will notice that the subtitle is not shown