fix to "okmap becomes complex164 if left unattended"

[iabrilcabezas]

mnms/utils.py, add .astype(okmap.dtype, copy=False) to phase

def fourier_resample(imap, omap=None, shape=None, wcs=None, dtype=None):
    ...
    phase = np.exp(-2j*np.pi*(ky*shift[0] + kx*shift[1]))

    okmap = concurrent_op(np.multiply, okmap, phase)
    okmap = enmap.ndmap(okmap, omap.wcs)

    return irfft(okmap, omap=omap, n=omap.shape[-1], normalize='forward')

to

    phase = np.exp(-2j*np.pi*(ky*shift[0] + kx*shift[1])).astype(okmap.dtype, copy=False)

    okmap = concurrent_op(np.multiply, okmap, phase)
    okmap = enmap.ndmap(okmap, omap.wcs)

    return irfft(okmap, omap=omap, n=omap.shape[-1], normalize='forward')