Allow overriding of ubus service name.

Same as for the dbus, allow specifying ubus service name (namespace) on
the command line as an optional argument to --enable-ubus option.

Signed-off-by: Oldřich Jedlička <oldium.pro@gmail.com>

src/dnsmasq.h

@@ -1063,6 +1063,7 @@ extern struct daemon {
   unsigned int duid_enterprise, duid_config_len;
   unsigned char *duid_config;
   char *dbus_name;
+  char *ubus_name;
   char *dump_file;
   int dump_mask;
   unsigned long soa_sn, soa_refresh, soa_retry, soa_expiry;