patch 9.1.0081: X11 mouse-scrolling stutters

Problem:  X11 mouse-scrolling stutters
          (Ron Aaron, after 9.1.0064)
Solution: Handle GDK_SCROLL_SMOOTH fractional distance events
          (lilydjwg)

I don't know why, but with GDK_SMOOTH_SCROLL_MASK we get wheel events as
GDK_SCROLL_SMOOTH. What's more, one wheel scroll is counted as 1.5
distance in Wayland but 1.0 in X11.

I failed to find any docs on gtk.org about this.

fixes: #13987
closes: #13991

Signed-off-by: lilydjwg <lilydjwg@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 36f9dc0..408dd37 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    81,
+/**/
     80,
 /**/
     79,