nlcache: link_del: move log.info after get_ifindex check

if the link doesn't exists get_ifindex will raise an exception
new code in the bridge module simply call link_del on a dummy port
that may not exists. It was a bit confusing to see the log.info
stating that a port was getting removed...

Signed-off-by: Julien Fortin <julien@cumulusnetworks.com>

ifupdown2/lib/nlcache.py

@@ -2553,9 +2553,11 @@ class NetlinkListenerWithCache(nllistener.NetlinkManagerWithListener, BaseObject
         :param ifname:
         :return:
         """
-        self.logger.info("%s: netlink: ip link del %s" % (ifname, ifname))
         try:
             ifindex = self.cache.get_ifindex(ifname)
+
+            self.logger.info("%s: netlink: ip link del %s" % (ifname, ifname))
+
             debug = RTM_DELLINK in self.debug
 
             link = Link(RTM_DELLINK, debug, use_color=self.use_color)