Disable background highlighting of `DraculaDiffDelete` when appropriate

[speelbarrow]

Disable the background highlight for the DraculaDiffDelete group when:

• g:dracula_colorterm is false, AND
• has('gui_running') is false

Before:

After:

[benknoble]

Can you share a different diff? In that particular one I think the contrast in the first screenshot is tremendously helpful.

[dsifford]

Agree with @benknoble. I feel like having the contrast where an entire line is deleted helps people easily see where deletions occur.

[speelbarrow]

That's a fair point. I'm more-so thinking about the background on the symbol in the signs column, but that's something I can take up with the maintainers of that plugin. I'll go ahead and close this PR.

[speelbarrow]

Reopening -- I didn't realize Dracula set the GitSigns groups itself. Currently working on a way to override just GitSignsDelete to lose the bg in the same cases as above.

[benknoble]

Can you change the PR to just drop the reverted commit? No need for the noise in the history. (You can do this with an interactive rebase, for example.)

[speelbarrow]

Can you change the PR to just drop the reverted commit? No need for the noise in the history. (You can do this with an interactive rebase, for example.)

Dropped. Here are new before and after screenshots (changed the Terminal background to make the change more visible):

Before:

After:

[benknoble]

The visual changes LGTM. Still dealing with code indent.

@dsifford ?

[dsifford]

I'm cool with it if you are @benknoble (pending fixes to formatting)

[speelbarrow]

Formatting issues resolved. Sorry about the indent, didn't realize it got cut out when I squashed the commits.