fix freeze_attention when not set (forgot on occurence)

train.py

@@ -47,7 +47,12 @@ def t1_run_name_from_params(args):
         "nonorm" if args.dont_normalize else "norm"
     ])
 
-    if args.freeze_attention:
+    try:
+        freeze_attention = args.freeze_attention
+    except AttributeError:
+        freeze_attention = False
+
+    if freeze_attention:
         s = f"{s}_frozen"
     return s