Remove redundant validation logic

`bpmf_phrases` is guaranteed to have entries from `bpmf_chars`, and so
we only need to validate data when reading from `PhraseFreq.txt`.

Source/Data/bin/cook.py

@@ -144,12 +144,8 @@
         phrases[mykey] = myvalue
 
     for (mykey, myvalue) in phrases.items():
-        try:
-            readings = bpmf_phrases[mykey]
-        except:
-            sys.exit('[ERROR] %s key mismatches.' % mykey)
+        readings = bpmf_phrases.get(mykey)
 
-        # print mykey
         if readings:
             # 剛好一個中文字字的長度目前還是 3 (標點、聲調好像都是2)
             if len(mykey) > 3: