don't open a temporary file if the trace level is set to zero

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

@@ -340,9 +340,11 @@ public class SessionRemote extends SessionWithState implements DataHandler {
             int level = Integer.parseInt(traceLevelFile);
             String prefix = getFilePrefix(SysProperties.CLIENT_TRACE_DIRECTORY);
             try {
+                traceSystem.setLevelFile(level);
+                if (level > 0) {
                     String file = FileUtils.createTempFile(prefix, Constants.SUFFIX_TRACE_FILE, false, false);
                     traceSystem.setFileName(file);
-                traceSystem.setLevelFile(level);
+                }
             } catch (IOException e) {
                 throw DbException.convertIOException(e, prefix);
             }