Fix GDB/LLDB unit tests to use KSharedConfig instead of separate KConfig

Authored by kossebau on Jul 25 2018, 11:59 AM.

Description

Fix GDB/LLDB unit tests to use KSharedConfig instead of separate KConfig

Summary:
Avoids issues with sync'ing from file-system between the different
working memory config instances

Reviewers: KDevelop, qi437103

Subscribers: kdevelop-devel

Tags: KDevelop

Differential Revision: https://phabricator.kde.org/D14365