Added the KeyError handling in delete_callback()
Added the KeyError handling in delete_callback()

stscieisenhamer/ginga,pllim/ginga,rupak0577/ginga,Cadair/ginga,ejeschke/ginga,Cadair/ginga,ejeschke/ginga,naojsoft/ginga,rajul/ginga,rajul/ginga,Cadair/ginga,stscieisenhamer/ginga,pllim/ginga,naojsoft/ginga,rupak0577/ginga,rajul/ginga,rupak0577/ginga,pllim/ginga,ejeschke/ginga,stscieisenhamer/ginga,naojsoft/ginga