ignore utility method for (de)serialization

src/main/java/com/commafeed/backend/model/ApplicationSettings.java

@@ -12,6 +12,8 @@ import javax.xml.bind.annotation.XmlRootElement;
 import org.apache.commons.lang3.time.DateUtils;
 import org.apache.log4j.Level;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
 @Entity
 @Table(name = "APPLICATIONSETTINGS")
 @SuppressWarnings("serial")
@@ -43,6 +45,7 @@ public class ApplicationSettings extends AbstractModel {
 	@Column(length = 255)
 	private String announcement;
 
+	@JsonIgnore
 	public Date getUnreadThreshold() {
 		int keepStatusDays = getKeepStatusDays();
 		return keepStatusDays > 0 ? DateUtils.addDays(new Date(), -1 * keepStatusDays) : null;