fix spacing in certgen.py
diff --git a/examples/certgen.py b/examples/certgen.py
index bf11c6e..53c19b1 100644
--- a/examples/certgen.py
+++ b/examples/certgen.py
@@ -45,7 +45,7 @@
     req = crypto.X509Req()
     subj = req.get_subject()
 
-    for key,value in name.items():
+    for key, value in name.items():
         setattr(subj, key, value)
 
     req.set_pubkey(pkey)