scripts/gen-egg-recipes: remove support for eggs without tags directory
scripts/gen-egg-recipes: remove support for eggs without tags directory

henrietta-cache doesn't support eggs without tags directory, so the
removed code doesn't make sense these days.

Signed-off-by: Mario Domenech Goulart <addb47291ee169f330801ce73520b96f2eaf20ea@ossystems.com.br>

OSSystems/meta-chicken,OSSystems/meta-chicken,OSSystems/meta-chicken