Newtab should not have an empty favicon

[srirambv]

Did you search for similar issues before submitting this one?
Yes

Expected behavior:
Newtab should not have an empty favicon

• Platform (Win7, 8, 10? macOS? Linux distro?):
  All

• Brave Version:
  0.12.10 RC1

• Screenshot if needed:
  

  edit: both newtab and about:blank

• Any related issues:

[bsclifton]

Thinking about this, the solution might be as easy as removing the icon from the about-blank.html / about-newtab.html 😄

Let's just remove the icon for these two pages altogether

[bbondy]

@bsclifton sounds like a good plan

[luixxiul]

Test plan: automated test should pass