patch 8.0.0574: get only one quickfix list after :caddbuf

Problem:    Get only one quickfix list after :caddbuf.
Solution:   Reset qf_multiline. (Yegappan Lakshmanan)
diff --git a/src/version.c b/src/version.c
index 7bafae1..28fe0b7 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    574,
+/**/
     573,
 /**/
     572,