This simple change enables the use of Guide button
for Windows 7 users, provided they have DirectX End-User
Runtimes installed. XInput 9.1.0 does not have the hidden
XInputGetStateEx export, so it was not possible to poll for
Guide button.
There are several reasons for this:
1. XINPUT_CAPS_FFB_SUPPORTED flag was introduced in Windows 8,
and therefore only supported by XInput 1.4
2. Despite the name, this flag does NOT indicate whether normal rumble
is supported. This flag is reserved for more complex force feedback,
and according to MSDN it may have went unused on Windows.
This fixes a future (the method is not used yet) bug where
XInputControllerInterface::GetControllerRumbleMotorCount would
erroreously report no rumble support.
