message: Fix variable shadowing in main.cpp
  main.cpp:2001:27: warning: declaration shadows a variable in the global namespace [-Wshadow]
  BOOST_SCOPE_EXIT(&PV, &fParallel) { PV->SetLocks(fParallel); }
  ^
  ./parallel.h:186:45: note: previous declaration is here
  extern std::unique_ptr<CParallelValidation> PV; // Singleton class
  ^
diff: @@ -1998,7 +1998,7 @@ bool ConnectBlock(const CBlock &block,
  // Begin Section for Boost Scope Guard
  {
  // Scope guard to make sure cs_main is set and resources released if we encounter an exception.
  - BOOST_SCOPE_EXIT(&PV, &fParallel) { PV->SetLocks(fParallel); }
  + BOOST_SCOPE_EXIT(&fParallel) { PV->SetLocks(fParallel); }
  BOOST_SCOPE_EXIT_END
  