Fix link to FeatureCollection in swing faq
Fix link to FeatureCollection in swing faq

The link was sending the user here:
http://docs.geotools.org/library/main/collection

Instead of here:
http://docs.geotools.org/latest/userguide/library/main/collection.html
geotools/geotools,geotools/geotools,geotools/geotools,geotools/geotools