there is backwards compatibility for GET CONFIG style configuration requests in
ndb_mgmd. None of the ndbd versions that use this couldn't possibly connect to a
5.0 or 5.1 cluster. remove the backwards compat

remove it


ndb/src/mgmsrv/Services.cpp:
  remove MGM_GET_CONFIG_BACKWARDS_COMPAT code.
  
  any client using GET CONFIG will just not work with modern NDB.
ndb/src/mgmsrv/Services.hpp:
  remove GET CONFIG support