[test] Ignor 'n' and 'i' in hb-unicode-encode

Allows accepting uniXXXX format.
diff --git a/test/shaping/hb_test_tools.py b/test/shaping/hb_test_tools.py
index 4e76d41..ba4a8bb 100644
--- a/test/shaping/hb_test_tools.py
+++ b/test/shaping/hb_test_tools.py
@@ -414,7 +414,7 @@
 	@staticmethod
 	def parse (s):
 		s = re.sub (r"0[xX]", " ", s)
-		s = re.sub (r"[<+>,;&#\\xXuU\n	]", " ", s)
+		s = re.sub (r"[<+>,;&#\\xXuUnNiI\n	]", " ", s)
 		return [int (x, 16) for x in s.split ()]
 
 	@staticmethod