Patch compiler error when building using nvcc
Patch compiler error when building using nvcc

If you compile using `nvcc` and pass the option `--expt-relaxed-constexpr` it will crash with an internal compiler error. This modification prevents using `constexpr` in `fmtlib` when compiling using `nvcc` and prevents the crash.

alabuzhev/fmt,alabuzhev/fmt,cppformat/cppformat,cppformat/cppformat,cppformat/cppformat,alabuzhev/fmt