patch 9.0.1993: warning about unused function definition

Problem:  warning about unused function definition
Solution: add ifdefs

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 2bb134a..7c5f3c4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1993,
+/**/
     1992,
 /**/
     1991,