patch 8.2.3387: compiler warning for non-static function

Problem:    Compiler warning for non-static function.
Solution:   Make the function static. (Dominique Pellé, closes #8816)
diff --git a/src/version.c b/src/version.c
index 1d65716..af45ded 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3387,
+/**/
     3386,
 /**/
     3385,