Mapfile typo in selfcal-mask_high

[mknapp55]

The previous step (selfcal-createmap_high_image) creates the mapfile createmap_high_image.mapfile which contains the right image for the next step. Step selfcal-mask_high uses a different mapfile which contains a filename that doesn't exist (it's missing the 'MFS' piece near the end). I got it to run successfully by changing line 314 from image_high1.output.image_high1-image.fits.mapfile to createmap_high_image.output.mapfile.