Update rate range to match intceil

I doubt this would change any prediction at all, but this is more correct according to the code.

js/predictions.js

@@ -44,11 +44,11 @@ function intceil(val) {
 }
 
 function minimum_rate_from_given_and_base(given_price, buy_price) {
-  return 10000 * (given_price - 1) / buy_price;
+  return 10000 * (given_price - 0.99999) / buy_price;
 }
 
 function maximum_rate_from_given_and_base(given_price, buy_price) {
-  return 10000 * given_price / buy_price;
+  return 10000 * (given_price + 0.00001) / buy_price;
 }
 
 function* generate_pattern_0_with_lengths(given_prices, high_phase_1_len, dec_phase_1_len, high_phase_2_len, dec_phase_2_len, high_phase_3_len) {