patch 8.1.1683: dictionary with string keys is longer than needed

Problem:    Dictionary with string keys is longer than needed.
Solution:   Use *{key: val} for literaly keys.
diff --git a/src/version.c b/src/version.c
index efcdb3f..fb7e5c3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1683,
+/**/
     1682,
 /**/
     1681,