package/qt5: change upstream location

Upstream pushes their delivery archives in to places:
    https://download.qt.io/official_releases/
    https://download.qt.io/archive/

After a while, only the latter remains, whith the former being pruned
actively to contain only officially supported versions.

Switch to using the archive location, as it has everything, even the
latest versions.

Signed-off-by: "Yann E. MORIN" <yann.morin@orange.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/qt5/qt5.mk

@@ -13,7 +13,7 @@ QT5_VERSION_MAJOR = 5.6
 QT5_VERSION = $(QT5_VERSION_MAJOR).3
 QT5_SOURCE_TARBALL_PREFIX = opensource-src
 endif
-QT5_SITE = https://download.qt.io/official_releases/qt/$(QT5_VERSION_MAJOR)/$(QT5_VERSION)/submodules
+QT5_SITE = https://download.qt.io/archive/qt/$(QT5_VERSION_MAJOR)/$(QT5_VERSION)/submodules
 
 include $(sort $(wildcard package/qt5/*/*.mk))