fix: search box throw a error with no suggestions (#510)

Author: Liyuk

lib/default-theme/SearchBox.vue

@@ -118,6 +118,9 @@ export default {
       }
     },
     go (i) {
+      if (!this.showSuggestions) {
+        return
+      }
       this.$router.push(this.suggestions[i].path)
       this.query = ''
       this.focusIndex = 0