vo_gpu_next: restore initial hook param value

If the parameter is removed from the `glsl-shader-opts` list, it should
be restored to initial value.

video/out/vo_gpu_next.c

@@ -2133,6 +2133,11 @@ static void update_hook_opts(struct priv *p, char **opts, const char *shaderpath
     if (!mp_splitext(basename, &shadername))
         shadername = bstr0(basename);
 
+    for (int i = 0; i < hook->num_parameters; i++) {
+        const struct pl_hook_par *hp = &hook->parameters[i];
+        memcpy(hp->data, &hp->initial, sizeof(*hp->data));
+    }
+
     for (int n = 0; opts[n * 2]; n++) {
         struct bstr k = bstr0(opts[n * 2 + 0]);
         struct bstr v = bstr0(opts[n * 2 + 1]);