Ensure minimum height of rdetail_image_div
Ensure minimum height of rdetail_image_div

Ensure a min-height on rdetail_image_div in an attempt to prevent
the rdetail_summary_from_rec div from forcing the copy_hold_counts
div off the margins of the page (observed in Chrome on some -- but
not all -- records where there is no cover image available).

Signed-off-by: Jeff Godin <7b658ab2e5573260a7dc1c722b8df4a45dfe4eff@tadl.org>

tadl/Evergreen_templates_tadlskin