Fix login provider custom name not showing up on login page

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/components/User/AuthProvider.vue

@@ -1,13 +1,13 @@
 <template>
   <a
     class="button is-light"
-    v-if="Object.keys(SELECTED_PROVIDERS).includes(oauthProvider.id)"
+    v-if="isProviderSelected && oauthProvider.label === null"
     :href="`/auth/${oauthProvider.id}`"
   >
     <b-icon :icon="oauthProvider.id" />
     <span>{{ SELECTED_PROVIDERS[oauthProvider.id] }}</span></a
   >
-  <a class="button is-light" :href="`/auth/${oauthProvider.id}`" v-else>
+  <a class="button is-light" :href="`/auth/${oauthProvider.id}`" v-else-if="isProviderSelected">
     <b-icon icon="lock" />
     <span>{{ oauthProvider.label }}</span>
   </a>
@@ -22,5 +22,9 @@ export default class AuthProvider extends Vue {
   @Prop({ required: true, type: Object }) oauthProvider!: IOAuthProvider;
 
   SELECTED_PROVIDERS = SELECTED_PROVIDERS;
+
+  get isProviderSelected(): boolean {
+    return Object.keys(SELECTED_PROVIDERS).includes(this.oauthProvider.id);
+  }
 }
 </script>