api disconnect just after SCAN_TABREQ


ndb/src/kernel/blocks/dbtc/DbtcMain.cpp:
  1) add error insert for faking DISCONNECT of API just after SCAN_TABREQ
  2) handle error :-)
ndb/test/ndbapi/testScan.cpp:
  Add etstcase for bug 24447
ndb/test/run-test/daily-basic-tests.txt:
  Add etstcase for bug 24447