Backward compatibility with older versions of Stash was broken in drone 1.x.x

[peter-teslenko]

I have pretty old Atlassian Stash 4.3.3 + Web Post Hooks for Bitbucket Server 3.1.0 and Drone 0.5.x
When switching to drone version 1.x.x broke compatibility with older versions of Stash.
Stash 4.3.3 REST API have no webhooks just hooks. Webhooks appear in newer versions of Stash.

I think that backward compatibility was broken after discussions in this thread.

Drone does not support Bitbucket Server (Stash) Pull Requests

After reading the source code and BitBucket REST API documentation, I believe Drone is using the wrong REST API resource. Drone currently uses /rest/projects/{projectKey}/repos/{repositorySlug}/settings/hooks/{hookKey}/enabled, using the PostReceive hook plugin (which will only trigger a call to drone when one does git push but will not generate a Pull Request related call). Drone should be using the new webhook API: /rest/projects/{projectKey}/repos/{repositorySlug}/webhooks, this API allows …

Is it possible to create an environment variable (Ex: DRONE_STASH_VERSION) that will be responsible for the generation of stash and will regulate the use of hooks or webhooks?