Bug: Bad behavior of refill-mode at end of org-mode file [9.4.4 (9.4.4-11-g9e8215-elpa @ /home/joh/.emacs.d/elpa/org-20210118/)]

[Johannes Mueller]

When using refill-mode in combination with org-mode adding a new section or a
list item at the end of the buffer, obviously because refill-mode steps in and
deletes the line break before the headline marker or the list marker.

Steps to reproduce:

1. Launch emacs -Q
2. Open a empty buffer and activate org-mode and refill-mode
3. Type `* This is a headline<M-RET>`

Expected behavior:

Buffer contents should be
```
* This is a headline
*
```

Actual behavior:

Buffer contens is
```
* this is a headline *
```

Obviously right after typing <M-RET> and thus inserting <line break>+"*"
refill-mode steps in and interprets the second line as part of the paragraph.

Remarks:

* The problem does not occur when there is text after the place where the new
headline is inserted

* The problem occurs with any kinds of headlines as well as with list items.


I tried to tweak paragraph-start, but I was not able to get the behavior I was
expecting.


Emacs  : GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.22, 
cairo version 1.17.3)
 of 2020-08-28
Package: Org mode version 9.4.4 (9.4.4-11-g9e8215-elpa @ /home/joh/.emacs.d/
elpa/org-20210118/)