Increase the statement_timeout value used in the prepared_xacts regression

test.  We have seen some buildfarm failures that seem to be due to this
limit being unexpectedly exceeded when the machine is under load.

src/test/regress/expected/prepared_xacts.out

@@ -157,7 +157,7 @@ SELECT gid FROM pg_prepared_xacts;
 (2 rows)
 
 -- pxtest3 should be locked because of the pending DROP
-set statement_timeout to 1000;
+set statement_timeout to 2000;
 SELECT * FROM pxtest3;
 ERROR:  canceling statement due to statement timeout
 reset statement_timeout;
@@ -172,7 +172,7 @@ SELECT gid FROM pg_prepared_xacts;
 (2 rows)
 
 -- pxtest3 should still be locked because of the pending DROP
-set statement_timeout to 1000;
+set statement_timeout to 2000;
 SELECT * FROM pxtest3;
 ERROR:  canceling statement due to statement timeout
 reset statement_timeout;

src/test/regress/sql/prepared_xacts.sql

@@ -102,7 +102,7 @@ SELECT * FROM pxtest2;
 SELECT gid FROM pg_prepared_xacts;
 
 -- pxtest3 should be locked because of the pending DROP
-set statement_timeout to 1000;
+set statement_timeout to 2000;
 SELECT * FROM pxtest3;
 reset statement_timeout;
 
@@ -113,7 +113,7 @@ reset statement_timeout;
 SELECT gid FROM pg_prepared_xacts;
 
 -- pxtest3 should still be locked because of the pending DROP
-set statement_timeout to 1000;
+set statement_timeout to 2000;
 SELECT * FROM pxtest3;
 reset statement_timeout;