Increase threshold for duplicate code

Increase number of lines that have to be similar to get a duplicate code
warning from 4 to 10. The warning triggers frequently on function
headers or longer configs which are partly similar.

Change-Id: I9a3a2d70a62332aef5d5d36f3655c75f2e0efa54

pylintrc

@@ -245,7 +245,7 @@ notes=FIXME,XXX,TODO
 [SIMILARITIES]
 
 # Minimum lines number of a similarity.
-min-similarity-lines=4
+min-similarity-lines=10
 
 # Ignore comments when computing similarities.
 ignore-comments=yes