patch 8.0.1766: expanding abbreviation doesn't work

Problem:    Expanding abbreviation doesn't work. (Tooth Pik)
Solution:   Return OK instead of FALSE and FAIL instead of TRUE. (Christian
            Brabandt)
diff --git a/src/version.c b/src/version.c
index f80e22a..a79e38b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1766,
+/**/
     1765,
 /**/
     1764,