examples/ct: drop signSCT() helper fn
examples/ct: drop signSCT() helper fn

daviddrysdale/trillian,RJPercival/trillian,AlCutter/trillian,gdbelvin/trillian,daviddrysdale/trillian,gtank/trillian,Martin2112/trillian,codingllama/trillian,Martin2112/trillian,gdbelvin/trillian,google/trillian,daviddrysdale/trillian,Martin2112/trillian,gtank/trillian,google/trillian,RJPercival/trillian,gdbelvin/trillian,AlCutter/trillian,codingllama/trillian