0.3/2014-08-30--collections.xml: fix migration on MySQL database.

I've just change case of the table name from COLLECTIONS to collections.

Fix the following exception:
MySQLSyntaxErrorException: Table 'mystamps.COLLECTIONS' doesn't exist

Correction for 227b9a5 commit.

Author: php-coder

src/main/resources/liquibase/version/0.3/2014-08-30--collections.xml

@@ -45,7 +45,7 @@
 		<comment>Creates collections for existing users</comment>
 
 		<sql>
-			INSERT INTO COLLECTIONS(user_id)
+			INSERT INTO collections(user_id)
 			SELECT id
 			FROM users
 			ORDER BY id