Don't segfault when no browse domains are configured in resolv.conf. Original patch from zml. Closes #162

Index: avahi-daemon/main.c
===================================================================
--- avahi-daemon/main.c	(revision 1524)
+++ avahi-daemon/main.c	(revision 1525)
@@ -317,6 +317,11 @@
     int n;
     char **p;
 
+    if (!resolv_conf_search_domains) {
+        avahi_server_set_browse_domains(avahi_server, NULL);
+        return;
+    }
+
     l = avahi_string_list_copy(config.server_config.browse_domains);
     
     for (p = resolv_conf_search_domains, n = 0; *p && n < BROWSE_DOMAINS_MAX; p++, n++) {