Linkerd2: `top` output has no column headers

[wmorgan]

The output of linkerd top has no column headers, making it unclear what is actually being reported. (2.4.0)

[aimof]

This problem seems to cause from this line

termbox.SetCell(x, y, c, termbox.AttrBold, termbox.ColorDefault)

The param termbox.AttrBold should be set color but is not.
So both forground and background colors are termbox.ColorDefault (black).

We should set color white.

termbox.SetCell(x, y, c, termbox.AttrBold|termbox.ColorWhite, termbox.ColorDefault)

I'll make PR.

[adleong]

@wmorgan @aimof on what environment are you seeing this issue? I tried in iterm and terminal on MacOS and couldn't reproduce it.

[wmorgan]

Oops, this was user error on my part. Sorry! (I somehow ended up with bold text being the same color as the terminal background... which is a great way to confuse yourself.)