patch 8.1.2359: cannot build without FEAT_FLOAT

Problem:    Cannot build without FEAT_FLOAT. (John Marriott)
Solution:   Fix #ifdefs around f_srand().
diff --git a/src/version.c b/src/version.c
index 7318a6a..04808b0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -738,6 +738,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2359,
+/**/
     2358,
 /**/
     2357,