If fetch_url failed to download the URL fail early with a proper error message. Fixes #5474 (#5476)

lib/ansible/modules/packaging/os/yum.py

@@ -225,6 +225,8 @@ def fetch_rpm_from_url(spec, module=None):
     package = os.path.join(tempdir, str(spec.rsplit('/', 1)[1]))
     try:
         rsp, info = fetch_url(module, spec)
+        if not rsp:
+            module.fail_json(msg="Failure downloading %s, %s" % (spec, info['msg']))
         f = open(package, 'w')
         data = rsp.read(BUFSIZE)
         while data: