vi: modify rules for oc

dictsource/vi_rules

@@ -798,7 +798,7 @@ ỵ	ỵ
         oẳ         o@4
         oẵ         o@5
         oặ         o@6
-		oc		   O#c
+		oc		   O#k
 
 .group ò
         ò          O2
@@ -819,7 +819,7 @@ ỵ	ỵ
         óa         o@3       //ó (A       w3
         óng        O#3
         óe         o&3
-        óc		   O#3c
+        óc		   O#3k
  
         
  
@@ -858,7 +858,7 @@ ỵ	ỵ
         ọa         o@6       //ọ (A       w6
         ọng        O#6
         ọe         o&6
-        ọc		   O#6c
+        ọc		   O#6k
  
         
  

phsource/ph_vietnam

@@ -416,6 +416,8 @@ phoneme O# // ong
   vwl  starttype #o  endtype #o
   IF thisPh(isFirstVowel) AND thisPh(isFinalVowel) AND thisPh(isWordEnd) THEN
 	length 240
+	ELIF nextPh(k) THEN
+	length 140
 	ELSE
 	length 200
 	ENDIF