patch 8.1.0174: after paging up and down fold line is wrong

Problem:    After paging up and down fold line is wrong.
Solution:   Correct the computation of w_topline and w_botline. (Hirohito
            Higashi)
diff --git a/src/version.c b/src/version.c
index de6f550..6b422e6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    174,
+/**/
     173,
 /**/
     172,