Create a constructor for KLocalizedStringPrivate

Summary:
The constructor avoids the following asan runtime errors
kdesrc/frameworks/ki18n/src/klocalizedstring.cpp:179:7: runtime error: load of value 3200171710, which is not a valid value for type 'VisualFormat'
kdesrc/frameworks/ki18n/src/klocalizedstring.cpp:179:7: runtime error: load of value 190, which is not a valid value for type 'bool'
kdesrc/frameworks/ki18n/src/klocalizedstring.cpp:179:7: runtime error: load of value 190, which is not a valid value for type 'bool'
kdesrc/frameworks/ki18n/src/klocalizedstring.cpp:179:7: runtime error: load of value 190, which is not a valid value for type 'bool'

Test Plan: start konsole

Reviewers: Frameworks, ilic

Reviewed By: ilic

Subscribers: ilic

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D11149