Add "static" to "values()" on search scopes (#1204)

Author: jmini

gitlab4j-models/src/main/java/org/gitlab4j/models/Constants.java

@@ -919,7 +919,7 @@ public static <T> SearchScope<T> forValue(String value) {
             return (SearchScope<T>) jsonLookup.get(value);
         }
 
-        public Set<String> values() {
+        public static Set<String> values() {
             return jsonLookup.keySet();
         }
 
@@ -975,7 +975,7 @@ public static <T> GroupSearchScope<T> forValue(String value) {
             return (GroupSearchScope<T>) jsonLookup.get(value);
         }
 
-        public Set<String> values() {
+        public static Set<String> values() {
             return jsonLookup.keySet();
         }
 
@@ -1030,7 +1030,7 @@ public static <T> ProjectSearchScope<T> forValue(String value) {
             return (ProjectSearchScope<T>) jsonLookup.get(value);
         }
 
-        public Set<String> values() {
+        public static Set<String> values() {
             return jsonLookup.keySet();
         }