patch 8.2.0308: 'showbreak' does not work for a very long line

Problem:    'showbreak' does not work for a very long line. (John Little)
Solution:   Check whether 'briopt' contains "sbr". (Ken Takata, closes #5523,
            closes #5684)
diff --git a/src/version.c b/src/version.c
index 373eb16..db00344 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    308,
+/**/
     307,
 /**/
     306,