patch 8.0.1479: insert mode completion state is confusing

Problem:    Insert mode completion state is confusing.
Solution:   Move ctrl_x_mode into edit.c.  Add CTRL_X_NORMAL for zero.
diff --git a/src/version.c b/src/version.c
index 6f0f78f..2ca6c5a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1479,
+/**/
     1478,
 /**/
     1477,