Fix silent exception swallow in LocalFsBlobStore.prepare()

If ClusterUtils.mkStormClusterState() threw (e.g. ZooKeeper unreachable),
the exception was caught and printed to stderr via e.printStackTrace(),
leaving stormClusterState null. Every subsequent blob store operation
(startSyncBlobs, setupBlobstore, blobSync) would then crash with a
NullPointerException rather than a meaningful error.

Rethrow as RuntimeException to match the existing pattern used a few
lines above for FileBlobStoreImpl initialization, and to surface the
root cause at startup instead of at first use.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: jnioche

storm-server/src/main/java/org/apache/storm/blobstore/LocalFsBlobStore.java

@@ -110,7 +110,7 @@ public void prepare(Map<String, Object> conf, String overrideBase, NimbusInfo ni
         try {
             this.stormClusterState = ClusterUtils.mkStormClusterState(conf, new ClusterStateContext(DaemonType.NIMBUS, conf));
         } catch (Exception e) {
-            e.printStackTrace();
+            throw new RuntimeException("Failed to initialize cluster state for LocalFsBlobStore", e);
         }
         timer = new Timer("BLOB-STORE-TIMER", true);
         this.leaderElector = leaderElector;