patch 8.2.2231: when "--remote file" is used "file" is not reloaded

Problem:    When "--remote file" is used "file" is not reloaded.
Solution:   When a :drop command is used for a file that is already displayed
            in a window and it has not been changed, check if it needs to be
            reloaded. (closes #7560)
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index a2b60c9..734949c 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -5171,6 +5171,15 @@
 	    {
 		goto_tabpage_win(tp, wp);
 		curwin->w_arg_idx = 0;
+		if (!bufIsChanged(curbuf))
+		{
+		    int save_ar = curbuf->b_p_ar;
+
+		    // reload the file if it is newer
+		    curbuf->b_p_ar = TRUE;
+		    buf_check_timestamp(curbuf, FALSE);
+		    curbuf->b_p_ar = save_ar;
+		}
 		return;
 	    }
 	}