Used proper config param for setting trigger pool size in TUP
Minimum long signal buffer set to 0.5M instead of 1M


ndb/src/common/mgmcommon/ConfigInfo.cpp:
  Minimum long signal buffer = 0.5M from 1M
ndb/src/kernel/blocks/dbtup/DbtupGen.cpp:
  Used max no of triggers to define trigger pool in TUP
ndb/src/kernel/blocks/trix/Trix.cpp:
  Removed unused construct wasting 0.5M of memory
ndb/src/kernel/blocks/trix/Trix.hpp:
  Removed unused construct wasting 0.5M of memory