Mark a module as non-marketplace

Although you don't want to customize marketplace modules at all, sometimes a appstore module has been customized over the years and is not really a marketplace module anymore (like Administration).

For maintainability, I'd like to unmark this module blue such that is at least visible that this module is not upgradable via the marketplace anymore.

I see 2 benefits:

• Future developers don't download updates accidentally overwriting customization
• Code quality and other tools (like function point analysis) will consider these as customized modules that require 'manual' maintanance.