Removing python2 conditional DEPENDS to avoid a circular dependency.

Signed-off-by: Eneas U de Queiroz <cote2004-github@yahoo.com>

Package is rewritten to be current type of python package with variants
but for backward compatibility the simplejson package name was left as
is and new Python3 specific package was named correctly as
python3-simplejson.

Signed-off-by: Karel Kočí <cynerd@email.cz>