irnetbox.py: Raise exception on unexpected response types
irnetbox.py: Raise exception on unexpected response types

I don't believe this is happening, but if it did happen it would be very
confusing to behave in any way other than raising an Exception.

martynjarvis/stb-tester,stb-tester/stb-tester,wmanley/stb-tester,martynjarvis/stb-tester,LewisHaley/stb-tester,LewisHaley/stb-tester,stb-tester/stb-tester,wmanley/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,LewisHaley/stb-tester,LewisHaley/stb-tester,wmanley/stb-tester,stb-tester/stb-tester,wmanley/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,LewisHaley/stb-tester,stb-tester/stb-tester,wmanley/stb-tester,LewisHaley/stb-tester,LewisHaley/stb-tester