patch 8.2.2924: superfluous extern declaration

Problem:    Superfluous extern declaration.
Solution:   Delete the declaration. (Ken Takata, closes #8307)
diff --git a/src/version.c b/src/version.c
index ee1dfa7..aaf27c1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2924,
+/**/
     2923,
 /**/
     2922,