Api refactoring fixes (#372)

* Fix JS error when logging in with bad credentials

* Remove duplicate error message if bad credentials

Error is already nicely displayed in LoginForm

frontend/src/api/users.js

@@ -32,7 +32,7 @@ export const userAPI = {
     let response = await apiReq.post(
       authURLs.token, 
       formData,
-      function() { return i18n.t('user.incorrect-username-or-password'); },
+      null,
       function() { return i18n.t('user.user-successfully-logged-in'); }
     );
     return response;

frontend/src/components/Login/LoginForm.vue

@@ -98,10 +98,9 @@ export default {
         this.clear();
         this.$store.commit("setToken", response.data.access_token);
         this.$emit("logged-in");
-      }
-
         let user = await api.users.self();
         this.$store.commit("setUserData", user);
+      }
 
       this.loading = false;
     },