qtcreator.qdoc: Fix unpaired markup

Fixes dabab8a (Merge branch 'mer-3.1' into next)

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>
MerOptionsPage: Use QTC_CHECK inst. of Q_ASSERT

Fixes dabab8a (Merge branch 'mer-3.1' into next)

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>