Fix osnet to not raise defect in ipnet. (#364)

* Debugging commit.

* Fix compilation issue.

* Remove debugging echoes.

chronos/transports/osnet.nim

@@ -834,14 +834,17 @@ elif defined(macosx) or defined(macos) or defined(bsd):
                       SockLen(sizeof(Sockaddr_in6)), ifaddress.host)
         if not isNil(ifap.ifa_netmask):
           var na: TransportAddress
-          var family = cast[cint](ifap.ifa_netmask.sa_family)
+          let family = int(ifap.ifa_netmask.sa_family)
           if family == osdefs.AF_INET:
             fromSAddr(cast[ptr Sockaddr_storage](ifap.ifa_netmask),
                       SockLen(sizeof(Sockaddr_in)), na)
+            if cint(ifaddress.host.family) == osdefs.AF_INET:
+              ifaddress.net = IpNet.init(ifaddress.host, na)
           elif family == osdefs.AF_INET6:
             fromSAddr(cast[ptr Sockaddr_storage](ifap.ifa_netmask),
                       SockLen(sizeof(Sockaddr_in6)), na)
-          ifaddress.net = IpNet.init(ifaddress.host, na)
+            if cint(ifaddress.host.family) == osdefs.AF_INET6:
+              ifaddress.net = IpNet.init(ifaddress.host, na)
 
         if ifaddress.host.family != AddressFamily.None:
           if len(res[i].addresses) == 0: