Fix selection of user's country

src/simulation/user.rs

@@ -49,7 +49,7 @@ impl User {
         let submits_reports = num < state.prob_user_submits_reports;
 
         // Probabilistically decide user's country
-        let num: f64 = rng.gen_range(0.0..1.0);
+        let mut num: f64 = rng.gen_range(0.0..1.0);
         let cc = {
             let mut cc = String::default();
             for (country, prob) in &state.probs_user_in_country {
@@ -58,7 +58,7 @@ impl User {
                     cc = country.to_string();
                     break;
                 } else {
-                    prob -= num;
+                    num -= prob;
                 }
             }
             cc