message: Add gitian PGP key for theStack
diff: @@ -28,6 +28,7 @@ D62A803E27E7F43486035ADBBCD04D8E9CCCAC2A Paul Rabahy
  37EC7D7B0A217CDB4B4E007E7FAB114267E4FA04 Peter Todd
  D762373D24904A3E42F33B08B9A408E71DAAC974 Pieter Wuille (Location: Leuven, Belgium)
  133EAC179436F14A5CF1B794860FEB804E669320 Pieter Wuille
  +6A8F9C266528E25AEB1D7731C2371D91CB716EA7 Sebastian Falbesoner (theStack)
  A8FC55F3B04BA3146F3492E79303B33A305224CB Sebastian Kung (TheCharlatan)
  ED9BDF7AD6A55E232E84524257FF9BDBCC301009 Sjors Provoost
  9EDAFF80E080659604F4A76B2EBB056FD847F8A7 Stephan Oeste (Emzy)
  