Remove chainbase mlock()

The mlock code was effectively inactive until 1.2.4. Enabling it has caused some unexpected support fallout. Remove it for now until a better solution is implemented in the future; performance will effectively be no worse than pre 1.2.4

src/chainbase.cpp

@@ -113,18 +113,6 @@ namespace chainbase {
                                                        ) );
          _segment->find_or_construct< environment_check >( "environment" )();
       }
-
-#ifndef _WIN32
-      if( mlock( _segment->get_address(), _segment->get_size() ) != 0 )
-      {
-         //we cannot use fc library here, which means that this message doesn't go to graylog even if you have configure it
-         //also it doesn't looks as nice as warnings generated by fc
-         //this message is for 1.0.2 because failing here would be incompatibel with 1.0
-         //for 1.1 it probably will be changed to throw an exception
-         std::cerr << "CHAINBASE:   Failed to pin chainbase shared memory (of size " << (_segment->get_size() / (1024.0*1024.0))
-                   << " MB) in RAM. Performance degradation is possible." << std::endl;
-      }
-#endif
 
       abs_path = bfs::absolute( dir / "shared_memory.meta" );
 
@@ -147,18 +135,6 @@ namespace chainbase {
          _rw_manager = _meta->find_or_construct< read_write_mutex_manager >( "rw_manager" )();
       }
 
-#ifndef _WIN32
-      if( mlock( _meta->get_address(), _meta->get_size() ) != 0 )
-      {
-         //we cannot use fc library here, which means that this message doesn't go to graylog even if you have configure it
-         //also it doesn't looks as nice as warnings generated by fc
-         //this message is for 1.0.2 because failing here would be incompatibel with 1.0
-         //for 1.1 it probably will be changed to throw an exception
-         std::cerr << "CHAINBASE:   Failed to pin chainbase metadata memory (of size " << _meta->get_size()
-                   << " bytes) in RAM. Performance degradation is possible." << std::endl;
-      }
-#endif
-
       bool* db_is_dirty   = nullptr;
       bool* meta_is_dirty = nullptr;