Drop unneeded duplicate addImportPath

Let KDeclarative::setupBindings() add the import paths: it too takes
paths from KGlobal::dirs()->findDirs("module", "imports"); it adds paths
in the correct (reverse) order [1].

[1] See kdelibs 400b9f2e9d10386bb175b6123fe0cdaafeaffe61 for further
details.

REVIEW: 110670