[influxdb image] command is ignored

Even though the official readme states that we can use `command` to specify custom commands, like changing the config file:


the entrypoint passes these args to `init-influxdb.sh`, but then `init-influxdb.sh` does not use them, losing all arguments.

Read the image entrypoint and init-influxdb.sh to trace how command arguments are passed and where they are discarded. Preserve the arguments so the documented custom command, including changing the config file, is honored, then verify the image uses the requested command instead of ignoring it.

Written by the indexing model from the issue text.