index: fix dead link

Closes #482.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>

index.html

@@ -2380,7 +2380,7 @@ local-pkg-list: $(LOCAL_PKG_LIST)</pre>
         <p>
         You might also have to provide a patch for it.
         In that case, have a look at other patches such as
-        <a href="https://github.com/mxe/mxe/blob/master/src/sdl-2-fix-dinput.patch">sdl-2-fix-dinput.patch</a>.
+        <a href="https://github.com/mxe/mxe/blob/master/src/sdl2-2-libtool.patch">sdl2-2-libtool.patch</a>.
         In particular, each patch file should be named as:
         </p>
         <pre>PACKAGE-PATCHNUMBER-DESCRIPTION.patch</pre>