Add log messages for IP checks during client install

The added log messages allow easier debugging of
IP related issues during ipa-client-install.

https://fedorahosted.org/freeipa/ticket/6331

Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>
Reviewed-By: Abhijeet Kasurde <akasurde@redhat.com>

client/ipa-client-install

@@ -1569,8 +1569,9 @@ def get_local_ipaddresses(iface=None):
             for ip in if_addrs.get(family, []):
                 try:
                     ips.append(ipautil.CheckedIPAddress(ip['addr']))
-                except ValueError:
-                    continue
+                    root_logger.debug('IP check successful: %s' % ip['addr'])
+                except ValueError as e:
+                    root_logger.debug('IP check failed: %s' % e)
     return ips