lcproc.collect_tfa_stats: more careful handling of all-nan magcol arrays
lcproc.collect_tfa_stats: more careful handling of all-nan magcol arrays

waqasbhatti/astrobase,waqasbhatti/astrobase,lgbouma/astrobase,waqasbhatti/astrobase,lgbouma/astrobase,lgbouma/astrobase