resource: Fix next_zmq_port_range using bvci file name

Change-Id: I293b7de1066ea69ccb0e495a69602ed56810018d
diff --git a/src/osmo_gsm_tester/core/resource.py b/src/osmo_gsm_tester/core/resource.py
index 223a8f9..a0ec552 100644
--- a/src/osmo_gsm_tester/core/resource.py
+++ b/src/osmo_gsm_tester/core/resource.py
@@ -219,7 +219,7 @@
         # Allocate continuous num_ports port between 2000 and 2200. returns base port.
         # Assumption: base port is always an odd number.
         num_ports = num_ports if num_ports % 2 == 0 else num_ports + 1
-        base_port = self.next_persistent_value('bvci', '2000', schema.uint16,
+        base_port = self.next_persistent_value('zmq_port', '2000', schema.uint16,
                                                lambda x: str(int(x)+num_ports) if int(x) < 2200 - num_ports else '2000', origin)
         return int(base_port)