check length before accessing text index

Author: bact

pythainlp/soundex/lk82.py

@@ -41,7 +41,8 @@ def lk82(text):
         res.append(text[0].translate(_TRANS1))
         text = text[1:]
     else:
-        res.append(text[1].translate(_TRANS1))
+        if len(text) > 0:
+            res.append(text[1].translate(_TRANS1))
         res.append(text[0].translate(_TRANS2))
         text = text[2:]