Default theme misses green border for heading on retractable blocks

[Kristina Hoeppner]

Removed gray border override for retractable blocks so theme's border colour can show instead.

https://reviews.mahara.org/#/c/10330/

[Steven (stevens-q)]

Commit hash: 44932baed15e08783b79a98e15ea21d8b01eaed2
Environment tested: Master
Browser tested: Chrome
Theme used: Default raw | Modern

PRECONDITIONS:
------------------------
1) Mahara user1 exists (no roles)
2) Portfolio page exists for user1 with the following blocks and is shared with public
     a) Text block 3 paragraphs Retractable set to no
     b) Text block 3 paragraphs Retractable set to yes
     c) Text block 3 paragraphs Retractable set to automatically retract
     d) Image block Retractable set to no
     e) Image block Retractable set to yes
     f) Image block Retractable set to automatically retract
3) Site theme is set to Default Raw

TEST STEPS:
------------------------
1) Site admin
2) Browse to the portfolio page as mentioned in the preconditions above
3) Verify the coloured border for heading on retractable blocks is displayed ✔
4) Browse to Admin menu > Configure site > Site options > Site settings
5) Change the theme to Modern
6) Verify the coloured border for heading on retractable blocks is displayed ✔

Catalyst QA Approved ✔

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/10330
Committed: https://git.mahara.org/mahara/mahara/commit/a2e583837d75d822b3d6a193a89c3a8aa6567ae1
Submitter: Robert Lyon (<email address hidden>)
Branch: master

commit a2e583837d75d822b3d6a193a89c3a8aa6567ae1
Author: Evonne <email address hidden>
Date: Wed Sep 11 10:12:19 2019 +1200

Bug 1843822: Default theme retractable block heading missing green border

Removed gray border override for retractable blocks so theme's
border colour can show instead.

behatnotneeded

Change-Id: Idee562cb6fc248d963801b2dd615f2e3827a630f