amarisoft_enb: Add missing default values in constructor

Change-Id: I61c04df14468b38cfe4afaaeb5404367838ff0a9
diff --git a/src/osmo_gsm_tester/amarisoft_enb.py b/src/osmo_gsm_tester/amarisoft_enb.py
index 5b4e99e..2ef713f 100644
--- a/src/osmo_gsm_tester/amarisoft_enb.py
+++ b/src/osmo_gsm_tester/amarisoft_enb.py
@@ -60,6 +60,7 @@
         super().__init__(suite_run, conf, 'amarisoftenb')
         self.ue = None
         self.run_dir = None
+        self.inst = None
         self._bin_prefix = None
         self.config_file = None
         self.config_sib1_file = None
@@ -69,6 +70,7 @@
         self.log_file = None
         self.process = None
         self.rem_host = None
+        self.remote_inst = None
         self.remote_config_file =  None
         self.remote_config_sib1_file = None
         self.remote_config_sib23_file = None