fix downloadFile method on ios; invalid native path and not using proper instance of CDVFile
fix downloadFile method on ios; invalid native path and not using proper instance of CDVFile

brendonparker/cordova-HTTP,silkimen/cordova-plugin-advanced-http,enricodeleo/cordova-HTTP,silkimen/cordova-plugin-advanced-http,DigitalsunrayMedia/cordova-HTTP,wymsee/cordova-HTTP,silkimen/cordova-plugin-advanced-http,yyfearth/cordova-plugin-http,silkimen/cordova-plugin-advanced-http,jeremychild/cordova-HTTP,denisbabineau/cordova-HTTP