patch 8.2.1164: text cleared by checking terminal properties not redrawn

Problem:    Text cleared by checking terminal properties not redrawn. (Alexey
            Radkov)
Solution:   Mark the screen characters as invalid. (closes #6422)
diff --git a/src/term.c b/src/term.c
index 3bda87c..07acc11 100644
--- a/src/term.c
+++ b/src/term.c
@@ -3732,6 +3732,7 @@
 	screen_stop_highlight();
 	term_windgoto(1, 0);
 	out_str((char_u *)"  ");
+	line_was_clobbered(1);
     }
 
     if (xcc_status.tr_progress == STATUS_GET)
@@ -3761,6 +3762,7 @@
 	screen_stop_highlight();
 	term_windgoto(2, 0);
 	out_str((char_u *)"           ");
+	line_was_clobbered(2);
     }
 
     if (did_send)