core: memlog and memdbg default value is L_DBG+1

- too verbose if just trying to use debug=3 in kamailio.cfg and mem
  operations are useful only on troubleshooting memory, which is not the
  typical troubleshooting case

cfg_core.c

@@ -64,7 +64,7 @@
 struct cfg_group_core default_core_cfg = {
 	L_WARN, 	/*!<  print only msg. < L_WARN */
 	LOG_DAEMON,	/*!< log_facility -- see syslog(3) */
-	L_DBG,  /*!< memdbg */
+	L_DBG+1,    /*!< memdbg */
 #ifdef USE_DST_BLACKLIST
 	/* blacklist */
 	0, /*!< dst blacklist is disabled by default */
@@ -115,7 +115,7 @@ struct cfg_group_core default_core_cfg = {
 	1500, /**< udp4_raw_mtu (1500 by default) */
 	-1,  /**< udp4_raw_ttl (auto detect by default) */
 	0,  /*!< force_rport */
-	L_DBG, /*!< memlog */
+	L_DBG+1, /*!< memlog */
 	3, /*!< mem_summary -flags: 0 off, 1 pkg_status, 2 shm_status,
 		4 pkg_sums, 8 shm_sums, 16 short_status */
 	0, /*!< mem_safety - 0 disabled */