patch 9.1.1176: wrong indent when expanding multiple lines

Problem:  wrong indentation of lastline when expanding multiple lines
Solution: Check OPENLINE_FORCE_INDENT flag in open_line() (glepnir)

closes: #16786

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/change.c b/src/change.c
index a3329bd..9d1b237 100644
--- a/src/change.c
+++ b/src/change.c
@@ -1672,7 +1672,8 @@
 		)
 	    && in_cinkeys(dir == FORWARD
 		? KEY_OPEN_FORW
-		: KEY_OPEN_BACK, ' ', linewhite(curwin->w_cursor.lnum));
+		: KEY_OPEN_BACK, ' ', linewhite(curwin->w_cursor.lnum))
+	    && !(flags & OPENLINE_FORCE_INDENT);
 
     // Find out if the current line starts with a comment leader.
     // This may then be inserted in front of the new line.