Don't try to read last-check-attempt property if we have an old version of 0launch.
treedd0ea212573438203189556a2892cde36d268c10
-rwxr-xr-x 3032 0alias
-rw-r--r-- 1488 0alias.1
-rwxr-xr-x 93 0launch
-rw-r--r-- 6348 0launch.1
-rwxr-xr-x 2187 0store
-rw-r--r-- 3623 0store.1
-rw-r--r-- 26536 COPYING
-rw-r--r-- 615 MANIFEST.in
-rw-r--r-- 2115 README
drwxr-xr-x - debian
-rwxr-xr-x 616 makedeb
-rwxr-xr-x 2759 makedist
-rw-r--r-- 67 setup.cfg
-rw-r--r-- 2148 setup.py
drwxr-xr-x - tests
drwxr-xr-x - zeroinstall