Always use Ascii Version of FormatMessage

if the UNICODE Macro is set FormatMessageW will be used, which expects errno_str as wchar_t*. So always use FormateMessageA.

plugins/ua_log_socket_error.h

@@ -16,7 +16,7 @@ extern "C" {
 #include <winsock2.h>
 #define UA_LOG_SOCKET_ERRNO_WRAP(LOG) { \
     char *errno_str = NULL; \
-    FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, \
+    FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, \
     NULL, WSAGetLastError(), \
     MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), \
     (LPSTR)&errno_str, 0, NULL); \