patch 8.1.1733: the man ftplugin leaves an empty buffer behind

Problem:    The man ftplugin leaves an empty buffer behind.
Solution:   Don't make new window and edit, use split. (Jason Franklin)
diff --git a/src/version.c b/src/version.c
index cdff0d3..e544975 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1733,
+/**/
     1732,
 /**/
     1731,