Consistently log when property stores is invalidated

PropStore was logging on some events that caused a need to refresh the
properties and not others.  Modified to consistently log whenever an
event caused the properties to be invalidated.

server/base/src/main/java/org/apache/accumulo/server/conf/store/PropStoreKey.java

@@ -152,6 +152,6 @@ public int hashCode() {
   @Override
   public String toString() {
     return this.getClass().getSimpleName() + "{" + getId().getClass().getSimpleName() + "="
-        + getId().canonical() + "'}";
+        + getId().canonical() + "}";
   }
 }

server/base/src/main/java/org/apache/accumulo/server/conf/util/PropSnapshot.java

@@ -113,28 +113,30 @@ private void updateSnapshot() {
   public void zkChangeEvent(final PropStoreKey<?> eventPropKey) {
     if (propStoreKey.equals(eventPropKey)) {
       requireUpdate();
+      log.debug("Saw zk change event for {} - update properties required", propStoreKey);
     }
   }
 
   @Override
   public void cacheChangeEvent(final PropStoreKey<?> eventPropKey) {
     if (propStoreKey.equals(eventPropKey)) {
       requireUpdate();
+      log.debug("Saw cache change event for {} - update properties required", propStoreKey);
     }
   }
 
   @Override
   public void deleteEvent(final PropStoreKey<?> eventPropKey) {
     if (propStoreKey.equals(eventPropKey)) {
       requireUpdate();
-      log.debug("Received property delete event for {}", propStoreKey);
+      log.debug("Received property delete event for {} - update properties required", propStoreKey);
     }
   }
 
   @Override
   public void connectionEvent() {
     requireUpdate();
-    log.debug("Received connection event - update properties required");
+    log.debug("Received connection event for {} - update properties required", propStoreKey);
   }
 
 }