BUG/MINOR: config: check the proper pointer to report unknown protocol

Check the protocol pointer and not the socket to report an unknown family
in servers or peers. This can never happen anyway, it's just to be completely
clean.
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 7e4db74..cd3a559d 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1309,7 +1309,7 @@
 		newpeer->data  = &raw_sock;
 		newpeer->sock_init_arg = NULL;
 
-		if (!sk) {
+		if (!newpeer->proto) {
 			Alert("parsing [%s:%d] : Unknown protocol family %d '%s'\n",
 			      file, linenum, newpeer->addr.ss_family, args[2]);
 			err_code |= ERR_ALERT | ERR_FATAL;
@@ -3951,7 +3951,7 @@
 			newsrv->proto = protocol_by_family(newsrv->addr.ss_family);
 			newsrv->data  = &raw_sock;
 
-			if (!sk) {
+			if (!newsrv->proto) {
 				Alert("parsing [%s:%d] : Unknown protocol family %d '%s'\n",
 				      file, linenum, newsrv->addr.ss_family, args[2]);
 				err_code |= ERR_ALERT | ERR_FATAL;