L2SS-357: Let unb2 sim test connect to the correct unb2 simulator address

devices/integration_test/client/test_unb2_sim.py

@@ -20,11 +20,12 @@ class TestUNB2Sim(base.IntegrationTestCase):
     def test_opcua_connection(self):
         """Check if we can connect to unb2-sim"""
 
-        client = Client("opc.tcp://recv-sim:4842")
+        client = Client("opc.tcp://unb2-sim:4844")
         root_node = None
 
+        client.connect()
+
         try:
-            client.connect()
             root_node = client.get_root_node()
         finally:
             client.disconnect()