patch 8.1.1468: the generated desktop files may be invalid

Problem:    The generated desktop files may be invalid.
Solution:   Check validity with desktop-file-validate. (Christian Brabandt,
            Will Thompson, closes #4480)
diff --git a/src/version.c b/src/version.c
index de5e0ab..443a114 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1468,
+/**/
     1467,
 /**/
     1466,