Core/Scripts: Fix uninitialized values in The Black Morass

Valgrind log:
 Conditional jump or move depends on uninitialised value(s)
  at 0x1798C2C: npc_medivh_bm::npc_medivh_bmAI::UpdateAI(unsigned int) (the_black_morass.cpp:192)
  by 0x11AEFC0: Creature::Update(unsigned int) (Creature.cpp:542)
  by 0x12E96F8: Trinity::ObjectUpdater::Visit(GridRefManager<Creature>&) (GridNotifiersImpl.h:45)

 Conditional jump or move depends on uninitialised value(s)
  at 0x1798C7E: npc_medivh_bm::npc_medivh_bmAI::UpdateAI(unsigned int) (the_black_morass.cpp:200)
  by 0x11AEFC0: Creature::Update(unsigned int) (Creature.cpp:542)
  by 0x12E96F8: Trinity::ObjectUpdater::Visit(GridRefManager<Creature>&) (GridNotifiersImpl.h:45)

 Conditional jump or move depends on uninitialised value(s)
  at 0x1798CB0: npc_medivh_bm::npc_medivh_bmAI::UpdateAI(unsigned int) (the_black_morass.cpp:205)
  by 0x11AEFC0: Creature::Update(unsigned int) (Creature.cpp:542)
  by 0x12E96F8: Trinity::ObjectUpdater::Visit(GridRefManager<Creature>&) (GridNotifiersImpl.h:45)

 Conditional jump or move depends on uninitialised value(s)
  at 0x1798CE2: npc_medivh_bm::npc_medivh_bmAI::UpdateAI(unsigned int) (the_black_morass.cpp:210)
  by 0x11AEFC0: Creature::Update(unsigned int) (Creature.cpp:542)
  by 0x12E96F8: Trinity::ObjectUpdater::Visit(GridRefManager<Creature>&) (GridNotifiersImpl.h:45)