add initialization of locales with native environment settings to the main function

src/Main/MainGui.cpp

@@ -97,6 +97,7 @@ private:
 
 int main( int argc, char ** argv )
 {
+    setlocale(LC_ALL, ""); // use native environment settings
 #if defined (FC_OS_LINUX) || defined(FC_OS_BSD)
     // Make sure to setup the Qt locale system before setting LANG and LC_ALL to C.
     // which is needed to use the system locale settings.