Remove HttpGet::error() function.

This function returns an internal enum value of QHttp (which is also
deprecated). It was only used for showing an error to the user / showing it in
the system trace. Since it is an enum value it doesn't have much value. Log /
show the error string instead.

Change-Id: I54b9b6026969f8108f779b02a04477f0ad9201ab

rbutil/rbutilqt/base/httpget.h

@@ -35,7 +35,6 @@ class HttpGet : public QObject
         bool getFile(const QUrl &url);
         void setProxy(const QUrl &url);
         void setProxy(bool);
-        QHttp::Error error(void);
         QString errorString(void);
         void setFile(QFile*);
         void setCache(const QDir&);