fix parse error:
https://github.com/ueno/libskk/pull/90

diff --git a/rules/default/rom-kana/default.json b/rules/default/rom-kana/default.json
index 6ddfce6..68dcff9 100644
--- a/rules/default/rom-kana/default.json
+++ b/rules/default/rom-kana/default.json
@@ -108,7 +108,7 @@
             "myi": ["", "みぃ" ],
             "myo": ["", "みょ" ],
             "myu": ["", "みゅ" ],
-            "n\'": ["", "ん" ],
+            "n'": ["", "ん" ],
             "na": ["", "な" ],
             "ne": ["", "ね" ],
             "ni": ["", "に" ],