Update VE core submodule to master (238c961)

New changes:
9426fe0 Check indentation was successful before trying again
a30d192 Add special case to de-indentation for slugs in listItems
91a275d Bold/italic icons for ar
523bbdb ve.js: Remove unused hasOwnProperty reference
016faa6 Add italic S icon, and set bold/italic for ksh
0910113 A strikethrough Y icon, and set bold/italic/strikethrough for fi
0c1c35d Allow annotations to remove other annotations
4305ccb Restore focus after node-destroying actions
55634da Localisation updates from https://translatewiki.net.

Change-Id: I8b390061fd7209245b3eff429954e6ec4271d8a3