run-tests: properly handle zero and multiple args
run-tests: properly handle zero and multiple args

The test for the help flag threw an error if there were 0 args, or if arg 1
was set to a space-separated list.  The -z tests would fail if the arg was
set to a space-separated list.

f-droid/fdroidserver,OneEducation/AppUniverse_Server,matlink/fdroidserver,matlink/fdroidserver,f-droid/fdroidserver,f-droid/fdroid-server,fdroidtravis/fdroidserver,OneEducation/AppUniverse_Server,f-droid/fdroidserver,OneEducation/AppUniverse_Server,f-droid/fdroid-server,matlink/fdroidserver,f-droid/fdroidserver,f-droid/fdroid-server,OneEducation/AppUniverse_Server,matlink/fdroidserver,matlink/fdroidserver,fdroidtravis/fdroidserver,f-droid/fdroid-server,f-droid/fdroid-server,fdroidtravis/fdroidserver,fdroidtravis/fdroidserver,OneEducation/AppUniverse_Server,f-droid/fdroidserver