Change `completelyIrregular` to `irregular`
Change `completelyIrregular` to `irregular`

To fix the following error
```
Dataset: 3D-Dachmodell LoD2 
A Validation Error occured at: Nf89d724ed19841ecacd5abec201a850e: Property: 'dct:accrualPeriodicity.' The frequency is expected from a controlled vocabulary http://purl.org/cld/freq. The given value could not be found in that vocabulary. Value received: 'http://purl.org/cld/freq/completelyIrregular' 
```
opendatazurich/ckanext-stadtzh-theme,opendatazurich/ckanext-stadtzh-theme,opendatazurich/ckanext-stadtzh-theme