Overflow visible when collapsible is expanded
Overflow visible when collapsible is expanded

This fixes a bug where the content of the collapsible was cut-off.

Re: https://github.com/hananils/datetime/issues/164

bauhouse/sym-todo-list,DeuxHuitHuit/symphony-2,johnpuddephatt/symphony-2,ljonka/symphony-2,bauhouse/sym-todo-list,mazedigital/jcilearn,DavidForster/symphony-2,blaXXabla/projet_test_symphony,DeuxHuitHuit/symphony-2,alexnantel88/symphony-2,michael-e/symphony-2,BloodBrother/symphony-2,BloodBrother/symphony-2,symphonycms/symphony-2,jurajkapsz/symphony-2,jonmifsud/symphony-2,alexnantel88/symphony-2,jonmifsud/symphony-2,twiro/symphony-2,roshinebagha/Symphony-Test,mazedigital/jcilearn,avanteweb/symphony-2,blaXXabla/projet_test_symphony,jurajkapsz/symphony-2,NikoMostWanted/symphony-2,NikoMostWanted/symphony-2,DavidForster/symphony-2,avanteweb/symphony-2,mazedigital/jcilearn,johnpuddephatt/symphony-2,twiro/symphony-2,brendo/symphony-2,michael-e/symphony-2,symphonycms/symphony-2,jensscherbl/symphony,roshinebagha/Symphony-Test,ljonka/symphony-2,jensscherbl/symphony,brendo/symphony-2