Update some commentary regarding an assumption

Author: buddhisthead

common/src/snapshot/mark_set_go.rs

@@ -128,7 +128,7 @@ impl Snapshot {
                                 .0
                                 .into_iter()
                                 .map(|(pool_id, params)| {
-                                    // Convert RewardAccount (Vec<u8>) to StakeAddress
+                                    // Convert RewardAccount (Vec<u8>) to StakeAddress (arbitralily chosen over ScripHash)
                                     let reward_account =
                                         StakeAddress::from_binary(&params.reward_account.0)
                                             .unwrap_or_else(|_|