test: Update pixel reference for TestStorageUsed.testUsed
test: Update pixel reference for TestStorageUsed.testUsed

Recently, the dialog got a bit wider, possibly due to the higher (and
thus slightly wider) PID numbers.

martinpitt/cockpit,cockpit-project/cockpit,martinpitt/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,cockpit-project/cockpit,cockpit-project/cockpit