cleanup_rings: fix python3 bytes/string type error

osclib/cleanup_rings.py

@@ -143,6 +143,7 @@ class CleanupRings(object):
     def check_buildconfig(self, project):
         url = makeurl(self.api.apiurl, ['build', project, 'standard', '_buildconfig'])
         for line in http_GET(url).read().splitlines():
+            line = line.decode('utf-8')
             if line.startswith('Preinstall:') or line.startswith('Support:'):
                 for prein in line.split(':')[1].split():
                     if prein not in self.bin2src: