glTF importer: fix bug in animation import

Problem occured when importing a gltf, delete objects, and importing a
new gltf, with same object / armature

io_scene_gltf2/blender/imp/gltf2_blender_animation_bone.py

@@ -170,6 +170,12 @@ class BlenderBoneAnim():
             action = bpy.data.actions.new(name)
         else:
             action = bpy.data.actions[name]
+            # Check if this action has some users.
+            # If no user (only 1 indeed), that means that this action must be deleted
+            # (is an action from a deleted action)
+            if action.users == 1:
+                bpy.data.actions.remove(action)
+                action = bpy.data.actions.new(name)
         if not obj.animation_data:
             obj.animation_data_create()
         obj.animation_data.action = bpy.data.actions[action.name]

io_scene_gltf2/blender/imp/gltf2_blender_animation_node.py

@@ -53,6 +53,12 @@ class BlenderNodeAnim():
         else:
             name = "Animation_" + str(anim_idx) + "_" + obj.name
         action = bpy.data.actions.new(name)
+        # Check if this action has some users.
+        # If no user (only 1 indeed), that means that this action must be deleted
+        # (is an action from a deleted action)
+        if action.users == 1:
+            bpy.data.actions.remove(action)
+            action = bpy.data.actions.new(name)
         if not obj.animation_data:
             obj.animation_data_create()
         obj.animation_data.action = bpy.data.actions[action.name]