add json setter for realm_roles

src/main/java/de/ozgcloud/operator/keycloak/user/OzgKeycloakUserSpec.java

@@ -96,6 +96,11 @@ class OzgKeycloakUserSpec {
 		public void setClientRoles(List<KeycloakUserSpecClientRole> clientRoles) {
 			this.clientRoles = clientRoles;
 		}
+
+		@JsonSetter(nulls = Nulls.AS_EMPTY)
+		public void setRealmRoles(List<KeycloakUserSpecRealmRole> realmRoles) {
+			this.realmRoles = realmRoles;
+		}
 	}
 
 	@Getter