patch 8.2.4798: t_8u option was reset even when set by the user

Problem:    t_8u option was reset even when set by the user.
Solution:   Only reset t_8u when using the default value. (closes #10239)
diff --git a/src/version.c b/src/version.c
index 6bed251..83d8e1b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4798,
+/**/
     4797,
 /**/
     4796,