patch 8.1.0523: opening window from quickfix leaves empty buffer behind

Problem:    Opening window from quickfix leaves empty buffer behind.
Solution:   Add qf_jump_newwin(). (Yegappan Lakshmanan, closes #2574)
diff --git a/src/version.c b/src/version.c
index 1058a2b..0ab7166 100644
--- a/src/version.c
+++ b/src/version.c
@@ -793,6 +793,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    523,
+/**/
     522,
 /**/
     521,