remove unsupported "thread_pool_size" parameter from conf files

targets/PROJECTS/GENERIC-LTE-EPC/CONF/gnb.band66.tm1.24PRB.usrpx300.conf

@@ -181,7 +181,6 @@ L1s = (
 {
   num_cc = 1;
   tr_n_preference = "local_mac";
-  thread_pool_size = 8;
   ofdm_offset_divisor = 8; #set this to UINT_MAX for offset 0
 }
 );

targets/PROJECTS/GENERIC-LTE-EPC/CONF/gnb.band66.tm1.25PRB.usrpx300.conf

@@ -179,7 +179,6 @@ L1s = (
 	{
 	num_cc = 1;
 	tr_n_preference = "local_mac";
-	thread_pool_size = 8;
 	ofdm_offset_divisor = 8; #set this to UINT_MAX for offset 0
 	}
 );

targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.band78.sa.fr1.106PRB.2x2.usrpn310.conf

@@ -235,7 +235,6 @@ L1s = (
   num_cc = 1;
   tr_n_preference = "local_mac";
   prach_dtx_threshold = 120;
-  thread_pool_size = 4;
 #  pucch0_dtx_threshold = 150;
 }
 );

targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.band78.sa.fr1.162PRB.2x2.usrpn310.conf

@@ -239,7 +239,6 @@ L1s = (
   num_cc = 1;
   tr_n_preference = "local_mac";
   prach_dtx_threshold = 120;
-  thread_pool_size = 8;
 #  pucch0_dtx_threshold = 150;
 }
 );