enb: Add attribute to set 'id'

Change-Id: I8ce296c7875d557062dc13e7093ce0400050f2ce
diff --git a/src/osmo_gsm_tester/templates/srsenb.conf.tmpl b/src/osmo_gsm_tester/templates/srsenb.conf.tmpl
index 94e724b..95b10f0 100644
--- a/src/osmo_gsm_tester/templates/srsenb.conf.tmpl
+++ b/src/osmo_gsm_tester/templates/srsenb.conf.tmpl
@@ -19,7 +19,8 @@
 #
 #####################################################################
 [enb]
-enb_id = 0x19B
+# need hex value here for enb_id due to bug: https://github.com/srsLTE/srsLTE/issues/485
+enb_id = ${hex(int(enb.id))}
 mcc = ${enb.mcc}
 mnc = ${enb.mnc}
 mme_addr = ${enb.mme_addr}