made the transfer history total an Option so it's not required in the schema

Author: reuvenpo

src/contract.rs

@@ -263,7 +263,7 @@ pub fn query_transactions<S: Storage, A: Api, Q: Querier>(
     let address = deps.api.canonical_address(account).unwrap();
     let (txs, total) = get_transfers(&deps.api, &deps.storage, &address, page, page_size)?;
 
-    let result = QueryAnswer::TransferHistory { txs, total };
+    let result = QueryAnswer::TransferHistory { txs, total: Some(total) };
     to_binary(&result)
 }
 

src/msg.rs

@@ -288,7 +288,7 @@ pub enum QueryAnswer {
     },
     TransferHistory {
         txs: Vec<Tx>,
-        total: u64,
+        total: Option<u64>,
     },
 
     ViewingKeyError {