SONAR suggestion - Synchronize initialization of static fields

Change-Id: I2ddf8220bda49f235ddfc5713174c11a147df354
diff --git a/web/gui/src/main/java/org/onosproject/ui/impl/ApplicationViewMessageHandler.java b/web/gui/src/main/java/org/onosproject/ui/impl/ApplicationViewMessageHandler.java
index 984dce2..6ed92a5 100644
--- a/web/gui/src/main/java/org/onosproject/ui/impl/ApplicationViewMessageHandler.java
+++ b/web/gui/src/main/java/org/onosproject/ui/impl/ApplicationViewMessageHandler.java
@@ -172,7 +172,7 @@
             // If the ID was not specified in the payload, use the name of the
             // most recently uploaded app.
             if (isNullOrEmpty(id)) {
-                id = ApplicationResource.lastInstalledAppName;
+                id = ApplicationResource.getLastInstalledAppName();
             }
 
             ApplicationId appId = as.getId(id);