fix calendar build

docs/javascripts/ics_calendar.js

docs/stylesheets/calendar.css

public/digitallabor/index.html

public/en/data/calendar.ics

public/en/javascripts/ics_calendar.js

public/en/sicherheit/ba-computerraum/index.html

public/en/sicherheit/ba-digitallabor/index.html

public/en/sicherheit/ba-it-edv/index.html

public/en/stylesheets/calendar.css

public/feed_rss_created.xml

public/feed_rss_updated.xml

public/javascripts/ics_calendar.js

public/metallbauwerkstatt/index.html

public/search/search_index.json

public/sicherheit/ba-computerraum/index.html

public/sicherheit/ba-digitallabor/index.html

public/sicherheit/ba-it-edv/index.html

public/sitemap.xml

public/sitemap.xml.gz

public/stylesheets/calendar.css