Module prefix in plain classes doesn't work

[AndreasVolkmann]

The following test fails.

@Test fun `common prefix per module - inner classes`() {
	// Arrange
	val prefix = "database"
	val expectedPort = 199
	class Nested(val port: Int)

	class Config {
		val database: Nested by module { this.prefix = "database" }
	}

	// Act
	val config = Arkenv.parse<Config>(arrayOf("--$prefix-port", expectedPort.toString()))

	// Assert
	expectThat(config.database).get { port } isEqualTo expectedPort
}

The module prefix in plain classes is not applied.