fix #4462 - ipynb: create_key_handler → t.store is undefined
fix #4462 - ipynb: create_key_handler → t.store is undefined

sagemathinc/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc,sagemathinc/smc