patch 7.4.1440
Problem:    Can't build on Windows.
Solution:   Change #ifdefs.  Only define isnan when used.
diff --git a/src/version.c b/src/version.c
index 28e16be..08ce414 100644
--- a/src/version.c
+++ b/src/version.c
@@ -744,6 +744,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1440,
+/**/
     1439,
 /**/
     1438,