make unauthorized error user-friendly

src/components/user_profile/user_profile.js

@@ -157,6 +157,8 @@ const UserProfile = {
             const errorMessage = get(reason, 'error.error')
             if (errorMessage === 'No user with such user_id') { // Known error
               this.error = this.$t('user_profile.profile_does_not_exist')
+            } else if (errorMessage == 'This API requires an authenticated user') {
+              this.error = this.$t('user_profile.unauthorized')
             } else if (errorMessage) {
               this.error = errorMessage
             } else {

src/i18n/en.json

@@ -1202,6 +1202,7 @@
     "user_profile": {
         "profile_does_not_exist": "Sorry, this profile does not exist.",
         "profile_loading_error": "Sorry, there was an error loading this profile.",
+        "unauthorized": "Please log in to view this profile.",
         "timeline_title": "User timeline",
         "field_validated": "Link Verified"
     },