Merge pull request #1696 from h2database/test_crash_api

TestCrashAPI-NPE: fix for #1354

h2/src/main/org/h2/engine/Session.java

@@ -411,7 +411,9 @@ public class Session extends SessionWithState implements TransactionStore.Rollba
         boolean wasLocked = database.lockMeta(this);
         try {
             modificationId++;
+            if (localTempTables != null) {
                 localTempTables.remove(table.getName());
+            }
             synchronized (database) {
                 table.removeChildrenAndResources(this);
             }