Remove background behind list-group-item-text

[Kristina Hoeppner]

In rare cases, when the page background is dark, the list-group-item-text had a white background instead of a transparent one.

An example of where this appears is in the "Latest changes I can view" block. The page description had a white background.

Please ask Evonne for what variable to change in the devtools / theme to trigger a background where the white would have been problematic.

https://reviews.mahara.org/#/c/10305/

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/10305
Committed: https://git.mahara.org/mahara/mahara/commit/e06f74d740d5fb3967697f325710da48f5325c18
Submitter: Robert Lyon (<email address hidden>)
Branch: master

commit e06f74d740d5fb3967697f325710da48f5325c18
Author: Evonne <email address hidden>
Date: Fri Sep 6 14:49:36 2019 +1200

Bug 1843238: Make List-group-item-text background transparent

Fixes list-group-item-text background from white to transparent.
An example of where this appears is in the "Latest changes I can view"
block. The page description had a white background, which did not look
good as there shouldn't have been a background.

behatnotneeded

Change-Id: Ib5b08d1a49b6c22458fbf8e0dfe846a00920ff22