生成代码RxHttpFormParam中警告问题，要求明确指定返回值

[pangli]

Return in function with expression body and without explicit return type. Use block body '{...}' or add an explicit return type. This will become an error in language version 2.5. See https://youtrack.jetbrains.com/issue/KTLC-288.

[liujingxing]

下个版本解决