Remove conditional code for old versions of Qt and Frameworks
Since Konqueror now needs at least Qt 5.12 and Frameworks 5.70 a number of conditional code needed to compile it with previous versions of Qt and Frameworks can be removed.
Since Konqueror now needs at least Qt 5.12 and Frameworks 5.70 a number of conditional code needed to compile it with previous versions of Qt and Frameworks can be removed.