GUACAMOLE-821:Add Japanese language support

extensions/guacamole-auth-duo/src/main/resources/guac-manifest.json

@@ -10,7 +10,8 @@
     ],
 
     "translations" : [
-        "translations/en.json"
+        "translations/en.json",
+        "translations/ja.json"
     ],
 
     "js" : [

extensions/guacamole-auth-duo/src/main/resources/translations/ja.json

@@ -0,0 +1,8 @@
+{
+
+    "LOGIN" : {
+        "INFO_DUO_VALIDATION_CODE_INCORRECT"    : "Duoの認証コードが間違っています。",
+        "INFO_DUO_AUTH_REQUIRED"                : "Duoで認証してください。"
+    }
+
+}