D20244: [AppletInterface] Check for corona before accessing it

[Aleix Pol Gonzalez]

apol accepted this revision.
This revision is now accepted and ready to land.

REPOSITORY
  R242 Plasma Framework (Library)

REVISION DETAIL
  https://phabricator.kde.org/D20244

To: broulik, #plasma, apol
Cc: kde-frameworks-devel, michaelh, ngraham, bruns