patch 8.1.0674: leaking memory when updating a single line

Problem:    Leaking memory when updating a single line.
Solution:   Do not call start_search_hl() twice.
diff --git a/src/version.c b/src/version.c
index 8240912..17f7733 100644
--- a/src/version.c
+++ b/src/version.c
@@ -800,6 +800,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    674,
+/**/
     673,
 /**/
     672,