patch 8.1.2343: using time() for srand() is not very random

Problem:    Using time() for srand() is not very random.
Solution:   use /dev/urandom if available

src/version.c

@@ -737,6 +737,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2343,
 /**/
     2342,
 /**/