Maint: Remove CYBERGHOST_GROUP (change)

- It does not make any sense with newer server data
- It was to be deprecated anyway

internal/constants/cyberghost.go

@@ -1,8 +1,6 @@
 package constants
 
 import (
-	"sort"
-
 	"github.com/qdm12/gluetun/internal/models"
 )
 
@@ -19,23 +17,6 @@ func CyberghostCountryChoices(servers []models.CyberghostServer) (choices []stri
 	return makeUnique(choices)
 }
 
-func CyberghostGroupChoices(servers []models.CyberghostServer) (choices []string) {
-	uniqueChoices := map[string]struct{}{}
-	for _, server := range servers {
-		uniqueChoices[server.Group] = struct{}{}
-	}
-
-	choices = make([]string, 0, len(uniqueChoices))
-	for choice := range uniqueChoices {
-		choices = append(choices, choice)
-	}
-
-	sortable := sort.StringSlice(choices)
-	sortable.Sort()
-
-	return sortable
-}
-
 func CyberghostHostnameChoices(servers []models.CyberghostServer) (choices []string) {
 	choices = make([]string, len(servers))
 	for i := range servers {