small modifications

- Jenkins: we don't need LOG_LEVEL=TRACE twice for the same binaries
- eth2_network_simulation: allow overriding NETWORK_TYPE and
  BOOTSTRAP_NODE_NETWORK_TYPE from the environment

Jenkinsfile

@@ -21,7 +21,7 @@ def runStages() {
 			parallel(
 				"tools": {
 					stage("Tools") {
-						sh "make -j${env.NPROC} LOG_LEVEL=TRACE"
+						sh "make -j${env.NPROC}"
 						sh "make -j${env.NPROC} LOG_LEVEL=TRACE NIMFLAGS='-d:NETWORK_TYPE=libp2p -d:testnet_servers_image'"
 					}
 				},

tests/simulation/vars.sh

@@ -27,8 +27,8 @@ MASTER_NODE=$(( TOTAL_NODES - 1 ))
 
 # You can run a mixed simulation of daemon and native libp2p nodes
 # by changing the variables below:
-NETWORK_TYPE=libp2p
-BOOTSTRAP_NODE_NETWORK_TYPE=libp2p
+NETWORK_TYPE=${NETWORK_TYPE:-"libp2p"}
+BOOTSTRAP_NODE_NETWORK_TYPE=${BOOTSTRAP_NODE_NETWORK_TYPE:-"libp2p"}
 
 SIMULATION_DIR="${SIM_ROOT}/data"
 METRICS_DIR="${SIM_ROOT}/prometheus"