Corrects disabling of arguments when creating Normal distribution (#69)

Author: Mayankm96

rsl_rl/modules/actor_critic.py

@@ -67,7 +67,7 @@ def __init__(
         self.std = nn.Parameter(init_noise_std * torch.ones(num_actions))
         self.distribution = None
         # disable args validation for speedup
-        Normal.set_default_validate_args = False
+        Normal.set_default_validate_args(False)
 
         # seems that we get better performance without init
         # self.init_memory_weights(self.memory_a, 0.001, 0.)