Doc: All \externalpage URLs come out wrong

External links are defined correctly in https://qt.gitorious.org/qt/qtbase/source/doc/global/externalsites/qt-webpages.qdoc but QDoc produces something different.

The links were fine back in Qt 5.1.

Examples

• http://doc-snapshot.qt-project.org/qt5-stable/qtdoc/qtmodules.html#qt-add-ons
  • "Qt Declarative" = \l {Qt Quick 1 Reference Documentation}

    points to http://doc-snapshot.qt-project.org/qt5-stable/activeqt/http-qt-project-org-doc-qt-4-8-qtquick.html

  • "Qt 4" = \l {Qt 4.8 Reference Documentation}

    points to http://doc-snapshot.qt-project.org/qt5-stable/activeqt/http-qt-project-org-doc-qt-4-8.html

• http://doc-snapshot.qt-project.org/qt5-stable/qtdoc/bughowto.html
  • "Qt Bug Tracker" = \l {Qt Bug Tracker}

    points to http://doc-snapshot.qt-project.org/qt5-stable/activeqt/http-bugreports-qt-project-org.html