Consider not hardcoding the default resource as demoResc

[messersc]

Hi M,

https://github.com/bihealth/irods-docker/blob/main/docker/templates/unattended_config.json.j2#L38

It looks like I am running into problems when trying to add a resource server to an already running icat because the resource is already existing and server_config.json gets autogenerated with demoResc and no way to change it.

irods_1  | 2023-09-13T12:13:06.966090157Z   Options passed to Popen:
irods_1  | 2023-09-13T12:13:06.966099668Z   
irods_1  | 2023-09-13T12:13:06.966108908Z   Return code: 4
irods_1  | 2023-09-13T12:13:06.966118265Z   Standard output:
irods_1  | 2023-09-13T12:13:06.966127643Z     Creating resource:
irods_1  | 2023-09-13T12:13:06.966136941Z     Name:             "demoResc"
irods_1  | 2023-09-13T12:13:06.966147147Z     Type:             "unixfilesystem"
irods_1  | 2023-09-13T12:13:06.966158199Z     Host:             "irods"
irods_1  | 2023-09-13T12:13:06.966167929Z     Path:             "/data/Vault"
irods_1  | 2023-09-13T12:13:06.966177598Z     Context:  ""
irods_1  | 2023-09-13T12:13:06.966187237Z   Error output:
irods_1  | 2023-09-13T12:13:06.966196747Z     remote addresses: 172.18.0.2 ERROR: rcGeneralAdmin failed with error -809000 CATALOG_ALREADY_HAS_ITEM_BY_THAT_NAME