app: search API is not available in private mode so disable it

src/App.js

@@ -97,7 +97,8 @@ export default {
         this.$store.state.instance.instanceSpecificPanelContent
     },
     showFeaturesPanel () { return this.$store.state.instance.showFeaturesPanel },
-    isMobileLayout () { return this.$store.state.interface.mobileLayout }
+    isMobileLayout () { return this.$store.state.interface.mobileLayout },
+    privateMode () { return this.$store.state.instance.private }
   },
   methods: {
     scrollToTop () {

src/App.vue

@@ -43,6 +43,7 @@
             class="nav-icon mobile-hidden"
             @toggled="onSearchBarToggled"
             @click.stop.native
+            v-if="currentUser || !privateMode"
           />
           <router-link
             class="mobile-hidden"