patch 8.2.1745: tiny version doesn't build

Problem:    Tiny version doesn't build.
Solution:   Add dummy ex_var() function.
diff --git a/src/version.c b/src/version.c
index 03a5581..bd5d607 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1745,
+/**/
     1744,
 /**/
     1743,