[mealie] Fix quoting of mealie environment variables

[Jonnobrow]

Description of the change

Pipe environment variables to quote to ensure that values such as "False" are not interpreted as boolean.

Benefits

All environment variables are correctly interpreted as strings, avoiding the need for additional quotation.

Possible drawbacks

N/A

Applicable issues

• fixes an issue raised in #1591

Additional information

Checklist

• [x] Title of the PR starts with chart name (e.g. [home-assistant])
• [x] Chart version bumped in Chart.yaml according to semver.
• [x] Chart artifacthub.io/changes changelog annotation has been updated in Chart.yaml. See Artifact Hub documentation for more info.
• [x] Variables have been documented in the values.yaml file.

[Diaoul]

Awesome! Thanks for the PR I was going to create one :laughing: