Refactor: code clean up

Author: jisungbin

Diff for: core/src/main/kotlin/io/github/sungbin/gitmessengerbot/core/bot/api/File.kt

@@ -13,7 +13,7 @@ import io.github.jisungbin.gitmessengerbot.common.core.Storage
 
 internal class File {
     fun save(path: String, content: String) = Storage.write(path, content)
-    fun read(path: String, _null: String? =  null) = Storage.read(path, _null)
+    fun read(path: String, _null: String? = null) = Storage.read(path, _null)
     fun append(path: String, content: String, appendPrefix: String) =
         Storage.append(path, content, appendPrefix)
 }