loguru.cpp: warning C4005: 'localtime_r': macro redefinition

When I compile with my Visual Studio (latest version), C++14 compiler, I get this warning:

loguru.cpp(52,1): warning C4005: 'localtime_r': macro redefinition

I checked the old loguru version (like 4 years old), and it was defined in the same place as localtime_x.
So I changed it back to localtime_x (so that the meaning of using localtime stays the same) and the couple of places it uses it I use localtime_x instead of localtime_r, exactly like it was in the old loguru version.

I wonder why it was changed to localtime_r and why I get that warning?