[fix] mark the token as a sensitive config option

so it's not logged by Kafka Connect

Author: jerrinot

connector/src/main/java/io/questdb/kafka/QuestDBSinkConnectorConfig.java

@@ -60,7 +60,7 @@ public static ConfigDef conf() {
                 .define(INCLUDE_KEY_CONFIG, Type.BOOLEAN, true, Importance.MEDIUM, INCLUDE_KEY_DOC)
                 .define(SYMBOL_COLUMNS_CONFIG, Type.STRING, null, Importance.MEDIUM, SYMBOL_COLUMNS_DOC)
                 .define(USERNAME, Type.STRING, "admin", Importance.MEDIUM, USERNAME_DOC)
-                .define(TOKEN, Type.STRING, null, Importance.MEDIUM, TOKEN_DOC)
+                .define(TOKEN, Type.PASSWORD, null, Importance.MEDIUM, TOKEN_DOC)
                 .define(TLS, Type.BOOLEAN, false, Importance.MEDIUM, TLS_DOC);
     }