Remove unnecessary line (#4260)

ml-agents/mlagents/trainers/sac/network.py

             self._create_memory_ins(m_size)
 
         hidden_critic = self._create_observation_in(vis_encode_type)
-        self.policy.output = self.policy.output
         # Use the sequence length of the policy
         self.sequence_length_ph = self.policy.sequence_length_ph