cmake-gui: Fix compile with Qt5 using UTF-8 internal encoding.

Because we already call [to|from]Local8Bit() with C strings where we are supposed to,
we do not need to specify UTF-8 encoding when converting C strings to QString.

Source/QtDialog/CMakeSetup.cxx

@@ -81,9 +81,7 @@ int main(int argc, char** argv)
 
 #if defined(KWSYS_CP_UTF8)
   QTextCodec* utf8_codec = QTextCodec::codecForName("UTF-8");
-  QTextCodec::setCodecForCStrings(utf8_codec);
   QTextCodec::setCodecForLocale(utf8_codec);
-  QTextCodec::setCodecForTr(utf8_codec);
 #endif
 
   // clean out standard Qt paths for plugins, which we don't use anyway