wrapping: trim any trailing blanks when cursor goes to next line

When typing a space causes both the succeeding word and the cursor to
be pushed to the next line, then this space (and any contiguous ones)
does need to be snipped (when --trimblanks is in effect).

This fixes https://savannah.gnu.org/bugs/?56180.

Bug existed since version 2.9.3, commit 91073be4.

src/text.c

@@ -1505,7 +1505,8 @@ bool do_wrap(void)
 		size_t tail_x = move_mbleft(line->data, wrap_loc);
 		size_t typed_x = move_mbleft(line->data, cursor_x);
 
-		while (tail_x != typed_x && is_blank_mbchar(line->data + tail_x)) {
+		while ((tail_x != typed_x || cursor_x >= wrap_loc) &&
+						is_blank_mbchar(line->data + tail_x)) {
 			openfile->current_x = tail_x;
 			do_delete();
 			tail_x = move_mbleft(line->data, tail_x);