fix crash in variable editor
fix crash in variable editor

BUG: 300224
FIXED-IN: 4.8.4

cmacq2/kate,hlamer/kate,sandsmark/kate,hlamer/kate,hlamer/kate,cmacq2/kate,hlamer/kate,hlamer/kate,jfmcarreira/kate,sandsmark/kate,hlamer/kate,hlamer/kate,hlamer/kate,DickJ/kate,hlamer/kate,jfmcarreira/kate,DickJ/kate,sandsmark/kate,DickJ/kate,hlamer/kate,sandsmark/kate,DickJ/kate,cmacq2/kate,jfmcarreira/kate