Rigify: clear the Armature animation data in addition to the Object.

After the change in PoseBone.bone behavior, drivers will be added there.

rigify/generate.py

@@ -126,6 +126,7 @@ def generate_rig(context, metarig):
     # Get rid of anim data in case the rig already existed
     print("Clear rig animation data.")
     obj.animation_data_clear()
+    obj.data.animation_data_clear()
 
     # Select generated rig object
     metarig.select_set(False)