patch 8.2.4858: K_SPECIAL may be escaped twice

Problem:    K_SPECIAL may be escaped twice.
Solution:   Avoid double escaping. (closes #10340)

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4858,
 /**/
     4857,
 /**/