Fix dummy values joint pe

@justin.janquart in https://git.ligo.org/angel.garron/golum_pipe/-/blob/global_checks/golum_pipe/golum_pipe/joint_pe.py#L134 you are passing all the arguments from image_1 to create the complete joint ini, but in the first argument you are passing config instead of img1_config. Bilby complains if the second image has three detectors but the first image only has two of them, since it tries to find the data for the missing detector. I fixed this issue by passing img1_config, so we are not mixing the arguments of the first and second image.