Fix multi tenant bean change (#982)

* FIX: beanChange has tenant-id

* FIX: NPE in DefaultServer.currentTenantId()

src/main/java/io/ebeaninternal/server/changelog/ChangeJsonBuilder.java

@@ -48,6 +48,9 @@ public class ChangeJsonBuilder {
     writeBeanTransactionDetails(gen, changeSet, position);
 
     gen.writeStringField("object", bean.getTable());
+    if (bean.getTenantId() != null) {
+      gen.writeStringField("tenantId", bean.getTenantId().toString());
+    }
     gen.writeStringField("objectId", bean.getId().toString());
     gen.writeStringField("change", bean.getType().getCode());
     gen.writeNumberField("eventTime", bean.getEventTime());

src/main/java/io/ebeaninternal/server/core/DefaultServer.java

@@ -314,7 +314,7 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
 
   @Override
   public Object currentTenantId() {
-    return currentTenantProvider.currentId();
+    return currentTenantProvider == null ? null : currentTenantProvider.currentId();
   }
 
   @Override

src/main/java/io/ebeaninternal/server/deploy/BeanDescriptor.java

@@ -837,7 +837,8 @@ public class BeanDescriptor<T> implements MetaBeanInfo, BeanType<T> {
   }
 
   private BeanChange newBeanChange(Object id, ChangeType changeType, Map<String, ValuePair> values) {
-    return new BeanChange(getBaseTable(), id, changeType, values);
+    Object tenantId = ebeanServer.currentTenantId();
+    return new BeanChange(getBaseTable(), tenantId, id, changeType, values);
   }
 
   public SqlUpdate deleteById(Object id, List<Object> idList, boolean softDelete) {