bug 36087: PostgresUpdater fails on 8.3.14

bug 36087: PostgresUpdater fails on 8.3.14

PostgresUpdater fails on PostgreSQL 8.3.14:

> Changing 'image.img_metadata' default value
> A database query syntax error has occurred.
> The last attempted database query was:
> "ALTER TABLE image ALTER img_metadata SET DEFAULT '\x'::bytea"
> from within function "".
> Database returned error "22P02: ERROR:  invalid input syntax for type
> bytea"

Patchset 2:

> Database returned error "42883: ERROR:  function
> generate_subscripts(int2vector, integer) does not exist
> LINE 7:     (SELECT generate_subscripts(isub.indkey, 1) AS g
>                     ^
> HINT:  No function matches the given name and argument types. You
> might need to add explicit type casts.
> "

Change-Id: I6e1811ded0eedad9c0eb0df715698c45aaf8e3f0