Be strict type

Author: koji-1009

studyplus-android-sdk/src/main/java/jp/studyplus/android/sdk/StudyplusError.kt

@@ -1,7 +1,7 @@
 package jp.studyplus.android.sdk
 
 sealed class StudyplusError {
-    class IOException(val throwable: Throwable) : StudyplusError()
+    class IOException(val e: java.io.IOException) : StudyplusError()
     object BadRequest : StudyplusError()
     object LoginRequired : StudyplusError()
     object ServerError : StudyplusError()