config: fix the default log level in tcmu.conf

Note: This patch maybe lost monthes ago.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>

tcmu.conf

@@ -7,9 +7,9 @@
 #    3: INFO
 #    4: DEBUG
 #    5: DEBUG SCSI CMD
-# And the default logging level is 2, if you want to change the
+# And the default logging level is 3, if you want to change the
 # default level, uncomment it and set your level number:
-# log_level = 2
+# log_level = 3
 #
 # Logging Directory Path
 # The default logging Directory path is /var/log/, uncomment it