fix for history and allMessages table

src/main/java/com/release11/klaus/model/Event.java

@@ -1,20 +1,12 @@
 package com.release11.klaus.model;
 
-import com.release11.klaus.utilis.BusinessKey;
 import lombok.*;
 import org.springframework.format.annotation.DateTimeFormat;
 import org.springframework.lang.Nullable;
 
-import javax.persistence.Entity;
-import java.time.LocalDate;
 import java.time.LocalDateTime;
-import java.time.LocalTime;
-import java.util.List;
-import java.util.Map;
-import java.util.UUID;
 
 @Data
-@Entity
 @Builder
 @ToString
 @NoArgsConstructor