tests/test_03_armor.py: fix syntax
tests/test_03_armor.py: fix syntax

Without this fix, there is an immediate failure when running pytest-3.

Signed-off-by: Daniel Kahn Gillmor <b1356865a0eefd1fb76a8b663fad027be4bc9b61@fifthhorseman.net>

SecurityInnovation/PGPy,SecurityInnovation/PGPy,SecurityInnovation/PGPy