alarms: remove default value for LogEntry received

Motivation:

The RESTful services are set to use an object mapper
which suppresses default values on the JSON objects
contained in an ArrayList.

Rather than check for undefined in the javascript
client, it makes more sense to set the value explicitly
rather than relying on the default.

Modification:

Remove the default value for the LogEntry received field
and set it in the DAO implementation.

Result:

The default value appears in the JSON object.

No visible changes to user.

Target: master
Request: 3.2
Require-notes: no
Require-book: no
Acked-by: Tigran

modules/dcache/src/main/java/org/dcache/alarms/LogEntry.java

@@ -97,7 +97,7 @@ private static String getFormattedDate(Date date) {
     private String notes;
     private Boolean closed   = false;
     private Boolean alarm    = false;
-    private Integer received = 1;
+    private Integer received;
 
     /*
      *  Reset by request processor according to current mapping.

modules/dcache/src/main/java/org/dcache/alarms/dao/impl/DataNucleusLogEntryStore.java

@@ -215,6 +215,7 @@ public void put(LogEntry entry) {
                      */
                     logger.trace("makePersistent alarm, key={}",
                                  entry.getKey());
+                    entry.setReceived(1);
                     insertManager.makePersistent(entry);
                     logger.trace("committing");
                 }