use standard library function for nan("") in datatype module

[00thirdeye00]

faker-cxx/src/modules/datatype/datatype.cpp

Line 16 in 540cea8

if (probability != nan(""))

this line will always be true. instead it might be better if we use standard library function to check if a number is nan using isnan(x)

[cieslarmichal]

agreed

[00thirdeye00]

I will create this as new issue