patch 8.1.1389: changes are not flushed when end and start overlap

Problem:    Changes are not flushed when end and start overlap. (Paul Jolly)
Solution:   When end of a previous changes overlaps with start of a new
            change, first flush listeners.

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1389,
 /**/
     1388,
 /**/