Make the predictable numbers start from 1

There is code that retries calling RAND_bytes() until it gets something
other than 0, which just hangs if we always return 0.

Reviewed-by: Rich Salz <rsalz@openssl.org>
GH: #2041

crypto/rand/md_rand.c

@@ -307,7 +307,7 @@ static int rand_bytes(unsigned char *buf, int num, int pseudo)
 
 #ifdef PREDICT
     if (rand_predictable) {
-        unsigned char val = 0;
+        unsigned char val = 1;
 
         for (i = 0; i < num; i++)
             buf[i] = val++;