Summary:
When a menu doesn't have any icons, space between check boxes and
text is twice as big as it should be.

Before
{F5714217, layout=center, size=full}

After
{F5714219, layout=center, size=full}

Test Plan: * open menu which has at least one checkbox and doesn't have any icons

Reviewers: #breeze, #vdg, hpereiradacosta

Reviewed By: hpereiradacosta

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D10584