Error constructor initializes _message std::string to nullptr; Visual C++ Warnings #224

In napi-inl.h, the Error:Error constructors initialize _message to nullptr.

In Visual Studio C++ with Static Analysis enabled ('VCCLCompilerTool: { 'AdditionalOptions': ['/analyze'] } in bindings.gyp)) a warning is given that the nullptr could be zero and doesn't adhere to the specification of std::basic_string.

warning C6387: 'Param(1)' could be '0'; this does not adhere to the specification for the function 'std::basic_string<char,std::char_traits,std::allocator >::{ctor}'. Lines: 1650

_message is std::string and not a pointer; it doesn't make sense to assign a null pointer literal to it. The explicit initialization of _message should be removed.