Fixed stackoverflow exception bug in FunctionalConfigApplicationContext.

Hi,

Unfortunately we can experience a stack overflow exception when calling our new cool companion methods on `FunctionalConfigApplicationContext`.

    val appContext = FunctionalConfigApplicationContext(classOf[MyFunctionalConfiguration])
    appContext[String] // Stack overflow
    ...
    appContext[String]("foo") // Yet another stack overflow

I've created two tests demonstrating the issue and submitted appropriate fix.

Cheers.