fix Cocoa build
fix Cocoa build

with change 83940f25, we used LIBS_PRIVATE on the Mac; somewhere
the line where we linked against the Mac libs in the network
kernel was lost.

Reviewed-By: Thiago

KDE/qt,KDE/qt,KDE/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,KDE/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,KDE/qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,RLovelett/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,KDE/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,RLovelett/qt,KDE/qt,igor-sfdc/qt-wk,RLovelett/qt,RLovelett/qt,KDE/qt,RLovelett/qt,RLovelett/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,RLovelett/qt