We should still be able to build with Qt 5.1 for the time being.

Also remove 3rdparty_upstream from from submodules, accidentally
added in https://codereview.qt-project.org/#change,67241


This fixes init-repository.py.

Change-Id: I08c095e4830581156efc3f069e00e733dda1ffd8
Reviewed-by: Adam Kallai <kadam@inf.u-szeged.hu>
Reviewed-by: Andras Becsi <andras.becsi@digia.com>

chromium @ 91532d5c

-Subproject commit 91532d5c5d39ed5f76a5d86a9c4c33a533f8a1ff

ninja @ 6f7ea464

-Subproject commit 6f7ea464bb9161ce2e15deb97977886de152c12d

lib/quick/quick.pro

@@ -6,6 +6,9 @@ IMPORT_VERSION = 1.0
 QT += qml quick
 QT_PRIVATE += qml-private quick-private gui-private core-private
 
+# Remove this as soon as we have a hard-dependency on Qt 5.2
+qtHaveModule(v8): QT_PRIVATE += v8-private
+
 INCLUDEPATH += ../
 
 # FIXME: all this should eventually be turned into QT += webenginecore