Hacky compile fix for mingw compile issue reported by bat3a on bf-committers

I've been using this fix in another branch locally, so it seems to work fine.
The other #ifdef checks should be checked on too, as __MINGW32__ and __MINGW64__
do NOT seem to be defined when compiling that file

extern/glog/src/windows/port.h

@@ -149,8 +149,13 @@ inline struct tm* localtime_r(const time_t* timep, struct tm* result) {
 }
 
 inline char* strerror_r(int errnum, char* buf, size_t buflen) {
+#ifdef FREE_WINDOWS
+  strncpy(buf, "Not implemented yet", buflen);
+  return buf;
+#else
   strerror_s(buf, buflen, errnum);
   return buf;
+#endif
 }
 
 #ifndef __cplusplus