[panel plugin] Make stable option also take effect when a panel is removed
[panel plugin] Make stable option also take effect when a panel is removed

Issue #4485

SidPresse/CodeMirror,hackmdio/CodeMirror,kerabromsmu/CodeMirror,schanzer/CodeMirror,mtaran-google/CodeMirror,codio/CodeMirror,notepadqq/CodeMirror,ficristo/CodeMirror,ejgallego/CodeMirror,mtaran-google/CodeMirror,pabloferz/CodeMirror,nightwing/CodeMirror,SidPresse/CodeMirror,dperetti/CodeMirror,rrandom/CodeMirror,crazy4chrissi/CodeMirror,hackmdio/CodeMirror,crazy4chrissi/CodeMirror,jayaprabhakar/CodeMirror,wingify/CodeMirror,nightwing/CodeMirror,namin/CodeMirror,kerabromsmu/CodeMirror,dperetti/CodeMirror,MarcelGerber/CodeMirror,codio/CodeMirror,MarcelGerber/CodeMirror,wingify/CodeMirror,SidPresse/CodeMirror,MarcelGerber/CodeMirror,namin/CodeMirror,wingify/CodeMirror,thomasjm/CodeMirror,kerabromsmu/CodeMirror,rrandom/CodeMirror,mtaran-google/CodeMirror,jkaplon/CodeMirror,pabloferz/CodeMirror,namin/CodeMirror,jayaprabhakar/CodeMirror,grzegorzmazur/CodeMirror,jkaplon/CodeMirror,ejgallego/CodeMirror,pabloferz/CodeMirror,jayaprabhakar/CodeMirror,grzegorzmazur/CodeMirror,notepadqq/CodeMirror,rrandom/CodeMirror,ficristo/CodeMirror,codio/CodeMirror,ficristo/CodeMirror,jkaplon/CodeMirror,ejgallego/CodeMirror,notepadqq/CodeMirror,thomasjm/CodeMirror,schanzer/CodeMirror,schanzer/CodeMirror,hackmdio/CodeMirror,grzegorzmazur/CodeMirror,thomasjm/CodeMirror,nightwing/CodeMirror,dperetti/CodeMirror,crazy4chrissi/CodeMirror