patch 8.1.1744: build error without the conceal feature

Problem:    Build error without the conceal feature.
Solution:   Define variables also without the conceal feature.
diff --git a/src/version.c b/src/version.c
index 1253846..df0bc83 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1744,
+/**/
     1743,
 /**/
     1742,