nullptr instead of NULL

code/MDLLoader.cpp

@@ -415,7 +415,7 @@ void MDLImporter::InternReadFile_Quake1() {
         // FIXME: the cast is wrong and cause a warning on clang 5.0
         // disable this code for now, fix it later
         ai_assert(false && "Bad pointer cast");
-        pcFirstFrame = NULL;
+        pcFirstFrame = nullptr; // Workaround: msvc++ C4703 error
 #else
         BE_NCONST MDL::GroupFrame* pcFrames2 = (BE_NCONST MDL::GroupFrame*)pcFrames;
         pcFirstFrame = (BE_NCONST MDL::SimpleFrame*)(&pcFrames2->time + pcFrames->type);