Fix PDO::inTransaction() test for pgsql

inTransaction() nowadays casts the in_transaction result to boolean.
I'm not sure whether the INERROR state should result in true or false.
For now I went with the result that we actually get.

ext/pdo_pgsql/tests/is_in_transaction.phpt

@@ -57,10 +57,10 @@ var_dump($db->inTransaction());
 ?>
 --EXPECT--
 Test PDO::PGSQL_TRANSACTION_INTRANS
-int(2)
+bool(true)
 Test PDO::PGSQL_TRANSACTION_IDLE
-int(0)
+bool(false)
 Test PDO::PGSQL_TRANSACTION_INERROR
-int(3)
+bool(true)
 Test PDO::PGSQL_TRANSACTION_IDLE
-int(0)
+bool(false)