QtNetworkAuth: Fix compiler warnings for QNX

agent:2022/03/10 05:16:24 build.go:394: /home/qt/work/qt/qtnetworkauth/tests/auto/oauth1/tst_oauth1.cpp: In member function 'void tst_OAuth1::getToken()':
agent:2022/03/10 05:16:24 build.go:394: /home/qt/work/qt/qtnetworkauth/tests/auto/oauth1/tst_oauth1.cpp:472:72: warning: 'void QMultiMap<Key, T>::insert(QMultiMap<Key, T>&&) [with Key = QString; T = QVariant]' is deprecated: Use unite() instead [-Wdeprecated-declarations]
agent:2022/03/10 05:16:24 build.go:394: modifiedHeaders.insert(QMultiMap<QString, QVariant>(parameters));
agent:2022/03/10 05:16:24 build.go:394: ^
agent:2022/03/10 05:16:24 build.go:394: In file included from /home/qt/work/install/target/include/QtCore/qvariant.h:47,
agent:2022/03/10 05:16:24 build.go:394: from /home/qt/work/install/target/include/QtCore/qabstractitemmodel.h:47,
agent:2022/03/10 05:16:24 build.go:394: from /home/qt/work/install/target/include/QtCore/QtCore:13,
agent:2022/03/10 05:16:24 build.go:394: from /home/qt/work/qt/qtnetworkauth/tests/auto/oauth1/tst_oauth1.cpp:29:
agent:2022/03/10 05:16:24 build.go:394: /home/qt/work/install/target/include/QtCore/qmap.h:1504:10: note: declared here
agent:2022/03/10 05:16:24 build.go:394: void insert(QMultiMap<Key, T> &&map)
agent:2022/03/10 05:16:24 build.go:394: ^~~~~~
agent:2022/03/10 05:16:24 build.go:394: /home/qt/work/qt/qtnetworkauth/tests/auto/oauth1/tst_oauth1.cpp: In member function 'void tst_OAuth1::prepareRequestSignature()':
agent:2022/03/10 05:16:24 build.go:394: /home/qt/work/qt/qtnetworkauth/tests/auto/oauth1/tst_oauth1.cpp:597:62: warning: 'void QMultiMap<Key, T>::insert(QMultiMap<Key, T>&&) [with Key = QString; T = QVariant]' is deprecated: Use unite() instead [-Wdeprecated-declarations]
agent:2022/03/10 05:16:24 build.go:394: authArgs.insert(QMultiMap<QString, QVariant>(extraParams));
agent:2022/03/10 05:16:24 build.go:394: ^
agent:2022/03/10 05:16:24 build.go:394: In file included from /home/qt/work/install/target/include/QtCore/qvariant.h:47,
agent:2022/03/10 05:16:24 build.go:394: from /home/qt/work/install/target/include/QtCore/qabstractitemmodel.h:47,
agent:2022/03/10 05:16:24 build.go:394: from /home/qt/work/install/target/include/QtCore/QtCore:13,
agent:2022/03/10 05:16:24 build.go:394: from /home/qt/work/qt/qtnetworkauth/tests/auto/oauth1/tst_oauth1.cpp:29:
agent:2022/03/10 05:16:24 build.go:394: /home/qt/work/install/target/include/QtCore/qmap.h:1504:10: note: declared here
agent:2022/03/10 05:16:24 build.go:394: void insert(QMultiMap<Key, T> &&map)
agent:2022/03/10 05:16:24 build.go:394: ^~~~~~