set networkID to testnet-2 (#1944)

testnet-2 is the current network as seen in the node-docker-setup: https://github.com/iotaledger/node-docker-setup/blob/5e280df2cca8fd2a1ddda28f90cefeea2b4a562c/testnet/config.json

config_testnet.json

@@ -1,6 +1,6 @@
 {
   "protocol": {
-    "targetNetworkName": "testnet-1",
+    "targetNetworkName": "testnet-2",
     "milestonePublicKeyCount": 7,
     "baseToken": {
       "name": "Shimmer",
@@ -88,4 +88,4 @@
       }
     ]
   }
-}
+}