fix flickering GO button in footer (bug 703251)

Author: cvan

media/css/impala/nojs.css

@@ -11,3 +11,7 @@
 #site-noinstall-apps {
     display: block;
 }
+
+form.go button {
+    display: inherit;
+}

templates/amo_footer.html

@@ -16,7 +16,7 @@
         </option>
       {%- endfor %}
     </select>
-    <button type="submit">{{ _('Go') }}</button>
+    <noscript><button type="submit">{{ _('Go') }}</button></noscript>
   </form>
 {% endblock %}