textproc/sigil: update to 0.9.11

For new features, see complete ChangeLog at
https://github.com/Sigil-Ebook/Sigil/releases/tag/0.9.11

• Bug Fixes

• after mend and prettify - put cursor at enclosing tag if possible
• allow both links in Preview and clicking in Preview to reposition CV
• fix new cursor repositioning under new tab ala Spellcheck
• fix prettyprinting of the mark tag in gumbo and sigil_bs4
• fix crash when tagname illegally (for xhtml) includes single or double quotes
• fix crash in Reports for non-wellformed xhtml that was okay under html5
• fix deletion of multiple css files when Book View is open (Windows)
• fix bug in reformat CSS with media queries
• fix bug in closing some tabs needlessly when linking stylesheets
• fix crash bug in gumbo parser under very strange circumstances
• remove empty guide elements in epub2 opf as epubcheck now flags these
• fix issue with index generation reordering spine entries under certain conditions

Reported by: portscout