tests: test_urls: require explicit distro= value

Most tests have a distro= value specified already. Make distro=none
required for those tests since they are limited

tests/test_urls.ini

@@ -44,6 +44,7 @@ kernelarg = inst.repo
 # Final centos5 trees, no distro detection since libosinfo doesn't track it
 [centos-5.11]
 url = http://vault.centos.org/5.11/os/x86_64
+distro = none
 
 # Latest centos 6 w/ i686
 [centos-6-latest]
@@ -187,6 +188,8 @@ distro = ubuntu17.10
 # Latest release
 [mageia6]
 url = http://distro.ibiblio.org/mageia/distrib/6/x86_64/
+distro = none
 # Devel tree
 [mageiacauldron]
 url = http://distro.ibiblio.org/mageia/distrib/cauldron/x86_64/
+distro = none

tests/test_urls.py

@@ -186,8 +186,12 @@ def _make_tests():
     urls = {}
     for name in cfg.sections():
         vals = dict(cfg.items(name))
-        d = _URLTestData(name, vals["url"],
-                vals.get("distro", None),
+        url = vals["url"]
+
+        if "distro" not in vals:
+            print("url needs an explicit distro= value: %s" % url)
+            sys.exit(1)
+        d = _URLTestData(name, url, vals["distro"],
                 vals.get("testxen", "0") == "1",
                 vals.get("testshortcircuit", "0") == "1",
                 vals.get("kernelarg", None),