OAK-8627: Avoid late-arriving lastRev update from crashed instance

DocumentNodeStore must be disposed before collection is dropped
Make call to dispose fail-safe in test tear down

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1867491 13f79535-47bb-0310-9956-ffa450edef68

oak-run/src/test/java/org/apache/jackrabbit/oak/run/DataStoreCommandTest.java

@@ -682,8 +682,13 @@ public MongoStoreFixture() {
             }
 
             @Override public void after() {
-                MongoUtils.dropCollections(c.getDBName());
-                nodeStore.dispose();
+                String dbName = c.getDBName();
+                try {
+                    nodeStore.dispose();
+                } catch (Exception e) {
+                    log.warn("dispose failed with exception", e);
+                }
+                MongoUtils.dropCollections(dbName);
             }
         }