Get rid of _param:influxdb_password

This parameter and influxdb_stacklight_password are redundant and they
have to be set to the same value.
diff --git a/heka/remote_collector/single.yml b/heka/remote_collector/single.yml
index 7b4050e..4b38afb 100644
--- a/heka/remote_collector/single.yml
+++ b/heka/remote_collector/single.yml
@@ -8,7 +8,7 @@
       influxdb_port: ${_param:influxdb_port}
       influxdb_database: ${_param:influxdb_database}
       influxdb_username: ${_param:influxdb_user}
-      influxdb_password: ${_param:influxdb_password}
+      influxdb_password: ${_param:influxdb_stacklight_password}
       aggregator_host: ${_param:heka_aggregator_host}
       aggregator_port: ${_param:aggregator_port}
       elasticsearch_host: ${_param:heka_elasticsearch_host}