patch 8.1.0726: redrawing specifically for conceal feature

Problem:    Redrawing specifically for conceal feature.
Solution:   Use generic redrawing methods.
diff --git a/src/edit.c b/src/edit.c
index bd6f606..33e0e67 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -1745,23 +1745,24 @@
     }
 #endif
 
-    if (must_redraw)
-	update_screen(0);
-    else if (clear_cmdline || redraw_cmdline)
-	showmode();		/* clear cmdline and show mode */
-# if defined(FEAT_CONCEAL)
+#if defined(FEAT_CONCEAL)
     if ((conceal_update_lines
 	    && (conceal_old_cursor_line != conceal_new_cursor_line
 		|| conceal_cursor_line(curwin)))
 	    || need_cursor_line_redraw)
     {
 	if (conceal_old_cursor_line != conceal_new_cursor_line)
-	    update_single_line(curwin, conceal_old_cursor_line);
-	update_single_line(curwin, conceal_new_cursor_line == 0
-		       ? curwin->w_cursor.lnum : conceal_new_cursor_line);
+	    redrawWinline(curwin, conceal_old_cursor_line);
+	redrawWinline(curwin, conceal_new_cursor_line == 0
+			    ? curwin->w_cursor.lnum : conceal_new_cursor_line);
 	curwin->w_valid &= ~VALID_CROW;
+	need_cursor_line_redraw = FALSE;
     }
-# endif
+#endif
+    if (must_redraw)
+	update_screen(0);
+    else if (clear_cmdline || redraw_cmdline)
+	showmode();		/* clear cmdline and show mode */
     showruler(FALSE);
     setcursor();
     emsg_on_display = FALSE;	/* may remove error message now */