Update tests/regtestenv.rs

Co-authored-by: Steve Myers <steve@notmandatory.org>

tests/regtestenv.rs

@@ -67,7 +67,7 @@ impl RegTestEnv {
             let balance = wallet.get_balance().unwrap();
             assert!(
                 balance.confirmed == 50_000_000_000,
-                "balance of wallet {} is {} but should be 5'000'000'000",
+                "balance of wallet {} is {} but should be 50_000_000_000",
                 i,
                 balance
             );