SCUBA2: strip the leading blank from the dec string if necessary

Astro::Coords returns positive declinations with a leading blank which
was the placeholder for the + sign. This space causes problems when
the position is used in an NDF section so strip it out here.
SCUBA2: pixel area not needed for calibration

The FCFs are designed to convert the signal in pW per pixel into
mJy/beam or /arcsec**2. The pixel size is not needed for this
calibration step, and is only required when calculating an integrated
flux.