cmake-gui: Remove explicit locale setup

Qt uses utf-8 encoding by default for versions >= Qt5.

Source/QtDialog/CMakeSetup.cxx

@@ -7,7 +7,6 @@
 #include <QDir>
 #include <QLocale>
 #include <QString>
-#include <QTextCodec>
 #include <QTranslator>
 #include <QtPlugin>
 
@@ -122,9 +121,6 @@ int main(int argc, char** argv)
 
   setlocale(LC_NUMERIC, "C");
 
-  QTextCodec* utf8_codec = QTextCodec::codecForName("UTF-8");
-  QTextCodec::setCodecForLocale(utf8_codec);
-
   // tell the cmake library where cmake is
   QDir cmExecDir(QApplication::applicationDirPath());
 #if defined(Q_OS_MAC)