update att_tx in config to improve 5g attach in our setup

ci-scripts/conf_files/enb.band7.tm1.fr1.25PRB.usrpb210.conf

@@ -260,7 +260,7 @@ RUs = (
     local_rf       = "yes"
     nb_tx          = 1
     nb_rx          = 1
-    att_tx         = 0
+    att_tx         = 3
     att_rx         = 0;
     bands          = [7];
     max_pdschReferenceSignalPower = -27;

ci-scripts/conf_files/gnb.band78.tm1.fr1.106PRB.usrpb210.conf

@@ -244,7 +244,7 @@ RUs = (
        local_rf       = "yes"
          nb_tx          = 1
          nb_rx          = 1
-         att_tx         = 0
+         att_tx         = 3
          att_rx         = 0;
          bands          = [7];
          max_pdschReferenceSignalPower = -27;