Validation warning when layer stored in project subfolder

[raherin]

When synchronising a project that has layers stored in a subfolder within the project, the plugin will give a warning during validation that the layer is not in the project directory, which is misleading.

To reproduce:

• Create a basic project in QGIS
• Upload the project to the Mergin Maps cloud
• Create a subfolder in the project directory
• Add or create a new layer for the project, store the layer in the subfolder just created
• Save and synchronise the project
• Mergin Maps will warn you that the layer is not in the project directory

Alternatively, you can use the attached zip file to create a new project and then make some changes in the project and try to synchronise.

layer_subfolders.zip