Not raise an Error if strict=False and --url for download command

it introduce a same behavior like without "--url" option

Closes: #211
Approved by: ignatenkobrain

plugins/download.py

@@ -100,7 +100,9 @@ def run(self):
                     print(url)
                 else:
                     msg = _("Failed to get mirror for package: %s") % pkg.name
-                    raise dnf.exceptions.Error(msg)
+                    if self.base.conf.strict:
+                        raise dnf.exceptions.Error(msg)
+                    logger.warning(msg)
             return
         else: 
             locations = self._do_downloads(pkgs)  # download rpms