D17529: [proxysetting] Fix build with NM 1.4

[Wolfgang Bauer]

wbauer added a reviewer: jgrulich.

REPOSITORY
  R282 NetworkManagerQt

REVISION DETAIL
  https://phabricator.kde.org/D17529

To: wbauer, jgrulich
Cc: kde-frameworks-devel, michaelh, ngraham, bruns