Remove search-query from searchbox in docs layout.

layouts/partials/docs_sidebar.html

@@ -12,7 +12,7 @@
   </button>
 
   {{ if eq site.Params.search.engine 1 }}
-  <input name="q" type="search" class="form-control" id="search-query" placeholder="{{ i18n "search_placeholder" }}" autocomplete="off">
+  <input name="q" type="search" class="form-control" placeholder="{{ i18n "search_placeholder" }}" autocomplete="off">
   {{ end }}
 </form>