Apparent bug converting to real

[mmcleod89]

Hi everyone, I think there might be an issue with this code (it appears in a few places but this particular example is from l1_g_proximal.h:

    return l1_proximal_real_constraint()
      ? call_l1_proximal(out, gamma, x.real().template cast<typename T1::Scalar>())
      : call_l1_proximal(out, gamma, x);

So this is trying to cast to type Scalar to enforce a real constraint. But isn't this class instantiated with complex in the case of the complex FB algorithm, or am I being very dumb? We instantiate SCALAR to complex in ImagingForwardBackward and this passes it on to ForwardBackward which knocks on to l1_g_proximal and l1_proximal.