patch 8.2.3691: build failure with small features

Problem:    Build failure with small features.
Solution:   Add #ifdef. (Dominique Pellé)
diff --git a/src/version.c b/src/version.c
index d7c2d69..e7f2c74 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3691,
+/**/
     3690,
 /**/
     3689,