[autotests] Stabilise colorcorrect test

Summary:
It crashes occasionally as the connection thread is still processing events
when the app is tearing down. These changes bring it in line with the
other tests using WAYLANDTEST_MAIN.

Test Plan:
Relevant test now passes.
Ran repeatedl without a crash

Reviewers: #kwin

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D17254

autotests/integration/colorcorrect_nightcolor_test.cpp

@@ -61,10 +61,12 @@ void ColorCorrectNightColorTest::initTestCase()
 
 void ColorCorrectNightColorTest::init()
 {
+    QVERIFY(Test::setupWaylandConnection());
 }
 
 void ColorCorrectNightColorTest::cleanup()
 {
+    Test::destroyWaylandConnection();
 }
 
 void ColorCorrectNightColorTest::testConfigRead_data()