gnb_stack_nr: init loglevel of common log channel

to avoid netsocket stuff to spam logs with:

2021-12-01T14:16:58.946080 [COMN   ] [D] [    0] Setting RTO_INFO options on SCTP socket. Association 0, Initial RTO 3000, Minimum RTO 1000, Maximum RTO 6000
2021-12-01T14:16:58.946084 [COMN   ] [D] [    0] Setting SCTP_INITMSG options on SCTP socket. Max attempts 3, Max init attempts timeout 5000
2021-12-01T14:16:58.946109 [COMN   ] [D] [    0] Successfully bound to address 10.8.1.22:0
2021-12-01T14:16:58.998936 [COMN   ] [D] [    0] RxSockets: socket fd=7 has been registered.
2021-12-01T14:16:58.999049 [COMN   ] [D] [    0] Successfully bound to address 10.8.1.22:2152
2021-12-01T14:16:58.999056 [COMN   ] [D] [    0] RxSockets: socket fd=8 has been registered.

srsgnb/src/stack/gnb_stack_nr.cc

@@ -69,6 +69,7 @@ int gnb_stack_nr::init(const gnb_stack_args_t& args_,
   stack_logger.set_level(srslog::str_to_basic_level(args.log.stack_level));
   ngap_logger.set_level(srslog::str_to_basic_level(args.log.s1ap_level));
   gtpu_logger.set_level(srslog::str_to_basic_level(args.log.gtpu_level));
+  srslog::fetch_basic_logger("COMN", false).set_level(srslog::str_to_basic_level(args.log.stack_level));
 
   mac_logger.set_hex_dump_max_size(args.log.mac_hex_limit);
   rlc_logger.set_hex_dump_max_size(args.log.rlc_hex_limit);
@@ -77,6 +78,7 @@ int gnb_stack_nr::init(const gnb_stack_args_t& args_,
   stack_logger.set_hex_dump_max_size(args.log.stack_hex_limit);
   ngap_logger.set_hex_dump_max_size(args.log.s1ap_hex_limit);
   gtpu_logger.set_hex_dump_max_size(args.log.gtpu_hex_limit);
+  srslog::fetch_basic_logger("COMN", false).set_hex_dump_max_size(args.log.stack_hex_limit);
 
   if (x2_ == nullptr) {
     // SA mode