Fix bogus overflow check (#361)
Fix bogus overflow check (#361)

Compilers LOVE optimizing `a + b < a` to false.  This code will never run in an
opt build.
vjn/rsocket-cpp,rsocket/rsocket-cpp,phoad/rsocket-cpp,phoad/rsocket-cpp,rsocket/rsocket-cpp,alexmalyshev/rsocket-cpp,phoad/rsocket-cpp,vjn/reactivesocket-cpp,vjn/rsocket-cpp,alexmalyshev/rsocket-cpp,rsocket/rsocket-cpp,phoad/rsocket-cpp,vjn/reactivesocket-cpp,ReactiveSocket/reactivesocket-cpp,vjn/reactivesocket-cpp,rsocket/rsocket-cpp,phoad/rsocket-cpp,ReactiveSocket/reactivesocket-cpp,alexmalyshev/rsocket-cpp,ReactiveSocket/reactivesocket-cpp,alexmalyshev/rsocket-cpp,vjn/rsocket-cpp