Revert "use internal lang state"

This reverts commit 6681f24c.

src/components/DictionaryView.vue

@@ -110,10 +110,11 @@ function navigate_to_article(self, origin) {
   self.article = null
   self.waiting_for_articles = true
 
+  const lang = self.$route.params.lang
 
-  axios.get(ARTICLE_ENDPOINT + self.lang + '/article/' + self.$route.params.id + ".json")
+  axios.get(ARTICLE_ENDPOINT + lang + '/article/' + self.$route.params.id + ".json")
   .then(function(response){
-    self.article = Object.assign(response.data, {'dictionary': self.lang, results: self.search_results})
+    self.article = Object.assign(response.data, {'dictionary': lang, results: self.search_results})
     self.error = null
   })
   .catch(function(error){