salt: add avahi-ui to DEPENDS
salt: add avahi-ui to DEPENDS

NILRT needs the salt-minion package provided by salt to depend on
the python-avahi package provided by the avahi-ui recipe. This is done
in the bbappend.

However because avahi-ui is not marked as a dependency for salt, a build
race is triggered. On some setups, depending on the build order, we get:

ERROR: Nothing RPROVIDES 'python-avahi' (but (...)/meta-cloud-services/meta-openstack/recipes-support/salt/salt_2016.3.0.bb RDEPENDS on or otherwise requires it)

Signed-off-by: Ioan-Adrian Ratiu <7ec73abcfe099fc5574c01312b62768070c80980@ni.com>

ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt