Zeroconf: catch both ValueError and KeyError in get()

Zeroconf: catch both ValueError and KeyError in get()

This prevents a traceback during discovery of available hosts.

--- a/hgext/zeroconf/Zeroconf.py	Sat Apr 30 15:20:27 2011 +0300
+++ b/hgext/zeroconf/Zeroconf.py	Sat Apr 30 07:30:38 2011 -0500
@@ -808,7 +808,7 @@
 		try:
 			list = self.cache[entry.key]
 			return list[list.index(entry)]
-		except KeyError:
+		except (KeyError, ValueError):
 			return None
 
 	def getByDetails(self, name, type, clazz):