fix last_ram_increase

contracts/eosio.system/src/eosio.system.cpp

@@ -85,14 +85,15 @@ namespace eosiosystem {
    }
 
    void system_contract::update_ram_supply() {
-      auto cbt = eosio::current_block_time();
+      const block_timestamp cbt = eosio::current_block_time();
+      const block_timestamp last_ram_increase = _gstate2.last_ram_increase
 
-      if( cbt <= _gstate2.last_ram_increase ) return;
+      if( cbt <= last_ram_increase ) return;
       _gstate2.last_ram_increase = cbt; // set timestamp of last ram increase/decrease or no change
-      // if ( _gstate2.new_ram_per_block == 0 ) return; // no new ram is issued
+      if ( _gstate2.new_ram_per_block == 0 ) return; // no new ram is issued
 
       auto itr = _rammarket.find(ramcore_symbol.raw());
-      int64_t new_ram = static_cast<int64_t>(cbt.slot - _gstate2.last_ram_increase.slot) * _gstate2.new_ram_per_block;
+      int64_t new_ram = static_cast<int64_t>(cbt.slot - last_ram_increase.slot) * _gstate2.new_ram_per_block;
       // if ( _gstate.max_ram_size + new_ram < _gstate.total_ram_bytes_reserved ) return; // no ram left to issue
       _gstate.max_ram_size += new_ram;