Skip null or missing URLs for S3

Author: Daman Arora

services/secondary-storage/controller/src/main/java/org/apache/cloudstack/secondarystorage/SecondaryStorageManagerImpl.java

@@ -1247,6 +1247,10 @@ public boolean finalizeVirtualMachineProfile(VirtualMachineProfile profile, Depl
     protected void addSecondaryStorageServerAddressToBuffer(StringBuilder buffer, List<DataStore> dataStores, String vmName) {
         List<String> addresses = new ArrayList<>();
         for (DataStore dataStore: dataStores) {
+            // S3 and other object stores may not have a URL, so better to skip them
+            if (dataStore == null || dataStore.getTO() == null || dataStore.getTO().getUrl() == null) {
+                continue;
+            }
             String url = dataStore.getTO().getUrl();
             String[] urlArray = url.split("/");