Backpatch: Fix typo in update scripts for some contrib modules.

Backpatch as discussed in 20140702192641.GD22738@awork2.anarazel.de
ff. as the error messages are user facing and possibly confusing.

Original commit: 6f9e39bc

contrib/hstore/hstore--1.0--1.1.sql

 /* contrib/hstore/hstore--1.0--1.1.sql */
 
--- complain if script is sourced in psql, rather than via CREATE EXTENSION
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
 \echo Use "ALTER EXTENSION hstore UPDATE TO '1.1'" to load this file. \quit
 
 ALTER EXTENSION hstore DROP OPERATOR => (text, text);

contrib/pg_stat_statements/pg_stat_statements--1.0--1.1.sql

 /* contrib/pg_stat_statements/pg_stat_statements--1.0--1.1.sql */
 
 -- complain if script is sourced in psql, rather than via ALTER EXTENSION
-\echo Use "ALTER EXTENSION pg_stat_statements UPDATE" to load this file. \quit
+\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.1'" to load this file. \quit
 
 /* First we have to remove them from the extension */
 ALTER EXTENSION pg_stat_statements DROP VIEW pg_stat_statements;