fix typo

Signed-off-by: JaySon-Huang <[email protected]>

Author: JaySon-Huang

tiflash/troubleshoot-tiflash.md

@@ -142,7 +142,7 @@ In this example, the warning message shows that TiDB does not select the MPP mod
 
 If TiFlash replicas consistently fail to be created since the TiDB cluster is deployed, or if the TiFlash replicas were initially created normally but then all or some tables fails to be created after a period of time, you can diagnose and resolve the issue by performing the following steps:
 
-1. Check whether PD enables the `Placement Rules` feature. This feature is enabled by default since v6.5.0:
+1. Check whether PD enables the `Placement Rules` feature. This feature is enabled by default since v5.0:
 
     {{< copyable "shell-regular" >}}