Change cover setting for default image size to false
Change cover setting for default image size to false

- cover=false accords to bestfit which was used before using cover settings
- cover=false is more likely the intended behaviour for the default setting
- not changed in 3.6-3.8 to avoid problems in existing webs

koala-framework/koala-framework,kaufmo/koala-framework,kaufmo/koala-framework,koala-framework/koala-framework,kaufmo/koala-framework