fix formatting error

generate.py

@@ -108,7 +108,9 @@ def retrieve_hosts():
                             break
                         host.append(alt)
 
-    req_set = set(s.strip() for s in config['excludes']['required'].split(',') if s.strip())
+    req_set = set(s.strip() for s in config['excludes']['required'].split(',')
+                  if s.strip())
+
     def intersects(s):
         cmp_set = s.copy()
         for x in s: