patch 8.2.3160: 'breakindent' does not work well for bulleted lists

Problem:    'breakindent' does not work well for bulleted and numbered lists.
Solution:   Add the "list" entry to 'breakindentopt'. (Christian Brabandt,
            closes #8564, closes #1661)
diff --git a/src/structs.h b/src/structs.h
index f1f8f32..5331183 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -3671,6 +3671,7 @@
     int		w_briopt_min;	    // minimum width for breakindent
     int		w_briopt_shift;	    // additional shift for breakindent
     int		w_briopt_sbr;	    // sbr in 'briopt'
+    int		w_briopt_list;      // additional indent for lists
 #endif
 
     // transform a pointer to a "onebuf" option into a "allbuf" option