Bug on v1.14.1 WMS service GetCapabilities request when using regex and values type dimensions in tileset #379

Hello Mapcache Team,

it seems that a bug has been introduced in v1.14.1 when requesting GetCapabilities on a WMS service with dimension in the tileset.
The request raises a Segmentation Fault when using 'regex' or 'values' types dimensions in the tileset. Note that WMTS service GetCapabilities request does not raise the error.
The bug is not present in v1.14.0 but i can be reproduced in v1.14.1 and v1.16.0.

I would assume this is linked with the dimension -> get_default_value in service_wms.c introduced in pull request #311
4df71c3#diff-0f3b5ab90fb19bee8e4eaf018a4adb4f3b5955aac23374b657dd5a79b0980041R341

Maybe 'regex' and 'values' types dimensions never initialize the get_default_value function pointer in dimension.c ?

Thanks