tests: fix up pure case of test-sqlitestore.t
This is clearly what the line should read based on the "force to zlib"
section below, so I'm guessing it just got overlooked during development.
Differential Revision: https://phab.mercurial-scm.org/D5151
Hello, Foobar
[b'Hello, Fo, =;:<o', b'Hello, Bar']