Merge pull request #6498 from PinZhang/fixtypo

Fixed typo

doc/TwoPhaseCommitDesign.md

@@ -142,7 +142,7 @@ The detailed design explains all the functionalities and interactions.
 
 Currently, transaction ids are issued by VTTablets (VTID), and those ids are considered local. In order to coordinate distributed transactions, a new system is needed to identify and track them. This is needed mainly so that the watchdog process can pick up an orphaned transaction and resolve it to completion.
 
-The DTID will be generated by taking the VTID of the MM and prefixing it with the keyspace, shard info and a sequence to prevent to prevent collisions. If the MM’s VTID was ‘1234’ for keyspace ‘order’ and shard ‘40-80’, then the DTID would be ‘order:40-80:1234’. A collision could still happen if there is a failover and the new vttablet’s starting VTID had overlaps with the previous instance. To prevent this, the starting VTID of the vttablet will be adjusted to a value higher than any used by the prepared GTIDs.
+The DTID will be generated by taking the VTID of the MM and prefixing it with the keyspace, shard info and a sequence to prevent collisions. If the MM’s VTID was ‘1234’ for keyspace ‘order’ and shard ‘40-80’, then the DTID would be ‘order:40-80:1234’. A collision could still happen if there is a failover and the new vttablet’s starting VTID had overlaps with the previous instance. To prevent this, the starting VTID of the vttablet will be adjusted to a value higher than any used by the prepared GTIDs.
 
 ## Prepare API