(chainbase sync) Remove chainbase mlock()
(chainbase sync) 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

EOSIO/eos,EOSIO/eos,EOSIO/eos,EOSIO/eos,EOSIO/eos