relocated string to config

[jpearce185]

Description

I took the hard coded signature string of the project team and moved it into the config.

Motivation and Context

This signature can now be used in more than one place without having to be hard coded, and reduces the amount of hard coded values.

Tests performed

I sent completed contact forms via email with the signature coming from the config rather than using a hard coded value.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project as found in the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[jpwhite4]

For consistency with the rest of XDMoD and to match the documentation in portal_settings.ini, I suggest that you use the MailTemplates::getMaintainerSignature() function since this includes the logic that sets the signature to the origanization name if the maintainer_email_signature setting is absent.

[jpwhite4]

Please squash and merge rather than merge.