Patch: Fix for Nan numbers

[gilbertf]

"google/protobuf/internal/decoder.py
299c299

< and (float_bytes[2] >= 128)):

    and (float_bytes[2] >= b'\x80')):

334c334

< and (double_bytes[6] >= 240)

    and (double_bytes[6] >= b'\xF0')"