internal clock in testing conf files

targets/PROJECTS/GENERIC-LTE-EPC/CONF/testing_enb.conf

@@ -263,7 +263,7 @@ RUs = (
          max_pdschReferenceSignalPower = -27;
          max_rxgain                    = 118;
          eNB_instances  = [0];
-         clock_src = "external";
+         clock_src = "internal";
     }
 );  
 

targets/PROJECTS/GENERIC-LTE-EPC/CONF/testing_gnb.conf

@@ -264,7 +264,7 @@ RUs = (
          max_pdschReferenceSignalPower = -27;
          max_rxgain                    = 114;
          eNB_instances  = [0];
-         clock_src = "external";
+         clock_src = "internal";
     }
 );