patch 8.2.4924: maparg() may return a string that cannot be reused

Problem:    maparg() may return a string that cannot be reused.
Solution:   use msg_outtrans_special() instead of str2special().
            (closes #10384)
diff --git a/src/version.c b/src/version.c
index f2e0d31..d790a75 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4924,
+/**/
     4923,
 /**/
     4922,