Fix typo

Author: crossle

library/src/main/kotlin/one/mixin/bot/vo/TransactionRequest.kt

@@ -17,4 +17,4 @@ data class TransactionRequest(
 data class OpponentMultisig(
     val receivers: List<String>,
     val threshold: Int
-)
+)

library/src/main/kotlin/one/mixin/bot/vo/TransactionResponse.kt

@@ -18,4 +18,4 @@ data class TransactionResponse(
     val memo: String?,
     @SerializedName("created_at")
     val createdAt: String
-)
+)