dict.has_key() has been deprecated in python3, as per the release d…

…ocs:

https://docs.python.org/3.0/whatsnew/3.0.html#builtins

Changed `has_key()` to use python's `in` syntax.

avahi-python/avahi-discover/avahi-discover.py

@@ -210,10 +210,10 @@ def browse_domain(self, interface, protocol, domain):
             self.new_service_type(interface, protocol, self.stype, domain)
 
     def new_domain(self,interface, protocol, domain, flags):
-        if self.zc_ifaces.has_key((interface,protocol)) == False:
+        if ((interface,protocol) in self.zc_ifaces) == False:
             ifn = self.get_interface_name(interface, protocol)
             self.zc_ifaces[(interface,protocol)] = self.insert_row(self.treemodel, None, ifn,None,interface,protocol,None,domain)
-        if self.zc_domains.has_key((interface,protocol,domain)) == False:
+        if ((interface,protocol,domain) in self.zc_domains) == False:
             self.zc_domains[(interface,protocol,domain)] = self.insert_row(self.treemodel, self.zc_ifaces[(interface,protocol)], domain,None,interface,protocol,None,domain)
         if domain != "local":
             self.browse_domain(interface, protocol, domain)