patch 8.1.2288: not using all space when popup with "topleft" flips to above

Problem:    Not using all space when popup with "topleft" flips to above.
Solution:   Recompute the height when a popup flips from below to above.
            (closes #5151)
diff --git a/src/version.c b/src/version.c
index 34e5b2f..d2baa1f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2288,
+/**/
     2287,
 /**/
     2286,