Update index.html

Author: AlserLab

sponsors/index.html

@@ -85,13 +85,13 @@
                                     Research
                                 </a>
                         </li>
-                        <li class="nav-item">
+                        <li class="nav-item active">
                             <a class="nav-link" href="/sponsors/index.html">
                                     Sponsors
                                     <span class="sr-only">(current)</span>
                                 </a>
                         </li>
-                        <li class="nav-item active">
+                        <li class="nav-item">
                             <a class="nav-link" href="/teaching/index.html">
                                     Teaching
                                 </a>