s3-printing: remove pcap_cache_loaded asserts

s3-printing: remove pcap_cache_loaded asserts

pcap_cache_loaded() assertions were added to the (re)load_printers()
functions, to ensure the caller had called pcap_cache_reload() prior to
reloading printer shares.

The problem is, pcap_cache_loaded() returns false if the the pcap_cache
contains no printer entries. i.e. pcap_cache_reload() has run but not
detected any printers.

Remove these assertions, correct call ordering is already enforced.

Signed-off-by: Günther Deschner <gd@samba.org>
The last 3 patches address bug #7836 (A newly added printer isn't visbile to
clients).