chore: drop orphaned i18n file

rel/i18n/emqx_connector_mqtt.hocon

@@ -1,21 +0,0 @@
-emqx_connector_mqtt {
-
-name.desc:
-"""Connector name, used as a human-readable description of the connector."""
-
-name.label:
-"""Connector Name"""
-
-num_of_bridges.desc:
-"""The current number of bridges that are using this connector."""
-
-num_of_bridges.label:
-"""Num of Bridges"""
-
-type.desc:
-"""The Connector Type."""
-
-type.label:
-"""Connector Type"""
-
-}