Remove two_phase variable from CreateReplicationSlotCmd struct.

Commit 19890a06 added the option to enable two_phase commits via
pg_create_logical_replication_slot but didn't extend the support of same
in replication protocol. However, by mistake, it added the two_phase
variable in CreateReplicationSlotCmd which is required only when we extend
the replication protocol.

Reported-by: Jeff Davis
Author: Ajin Cherian
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/64b9f783c6e125f18f88fbc0c0234e34e71d8639.camel@j-davis.com

src/backend/replication/walsender.c

@@ -954,7 +954,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
 		 */
 		ReplicationSlotCreate(cmd->slotname, true,
 							  cmd->temporary ? RS_TEMPORARY : RS_EPHEMERAL,
-							  cmd->two_phase);
+							  false);
 	}
 
 	if (cmd->kind == REPLICATION_KIND_LOGICAL)

src/include/nodes/replnodes.h

@@ -56,7 +56,6 @@ typedef struct CreateReplicationSlotCmd
 	ReplicationKind kind;
 	char	   *plugin;
 	bool		temporary;
-	bool		two_phase;
 	List	   *options;
 } CreateReplicationSlotCmd;