docs: update the docs of `writeBatchThreadLocal` in taos.cfg

packaging/cfg/taos.cfg

@@ -317,5 +317,5 @@ keepColumnName            1
 # taosc write batch timeout in milliseconds, maximum 2048, suggested value 2 ~ 100, default 10.
 # writeBatchTimeout     10
 
-# using thread local write batching. this option is not available when writeBatchSize = 0.:::
+# using thread local write batching. this option is not available when writeBatchSize = 0.
 # writeBatchThreadLocal 0
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