Makefile: fix name of cfgutils in group kstandard

- wrong name having '_' caused the module not to be packaged in debs
- reported by Klaus Darilion
(cherry picked from commit 78e097fb1f185796abeff27e5978bc82bdb6526f)

Makefile

@@ -197,7 +197,7 @@ module_group_experimental=tls oracle iptrtpproxy
 # Kamailio specific groups
 # Standard modules in K Debian distro
 module_group_kstandard=acc alias_db auth auth_db benchmark call_control \
-				cfg_utils db_text dialog dispatcher diversion domain drouting \
+				cfgutils db_text dialog dispatcher diversion domain drouting \
 				exec group htable imc kex maxfwd mi_datagram mi_fifo msilo \
 				nat_traversal nathelper path pdt permissions pike pv qos \
 				ratelimit regex registrar rr rtimer siptrace siputils sl sms \