CMake: Remove <locale.h> test

We're not using the <locale.h> header anywhere besides including it
for no purpose, so we can drop the test (and the inclusion).
Additionally, the header is part of standard C++.

CMakeLists.txt

@@ -199,7 +199,6 @@ check_cxx_symbol_exists(vasprintf stdio.h HAVE_VASPRINTF)
 include(CheckIncludeFileCXX)
 include(CheckIncludeFilesCXX)
 CHECK_INCLUDE_FILE_CXX(io.h HAVE_IO_H)
-CHECK_INCLUDE_FILE_CXX(locale.h HAVE_LOCALE_H)
 CHECK_INCLUDE_FILE_CXX(share.h HAVE_SHARE_H)
 CHECK_INCLUDE_FILE_CXX(signal.h HAVE_SIGNAL_H)
 CHECK_INCLUDE_FILE_CXX(stdint.h HAVE_STDINT_H)

src/config/C4Config.cpp

@@ -33,9 +33,6 @@
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
-#ifdef HAVE_LOCALE_H
-#include <clocale>
-#endif
 
 #ifdef USE_CONSOLE
 #define DONCOFF 0