* autogenerate JWT_SECRETS
Based on https://docs.gitea.io/en-us/command-line/#generate we will now autogenerate JWT_SECRETS if they are not defined.
In my opinion a much better idea than writing a value in the default config.
The check if the variables for the secrets are now 43 characters long i took out. Gitea generates itself suitable secrets, if the user given ones do not fit.
* drop ansible.builtin. syntax
* delete trailing whitespace
* Add gitea_group
This will add the `gitea_group: gitea` and will probably
RESOLVE https://github.com/thomas-maurice/ansible-role-gitea/issues/70
* update variable length
update variable length to make this role idempotent
* vars should not include special character
Old behavior is to download the binary of `gitea_version` every run,
then checksum it against the currently installed version to see if it needs
to be copied over.
New behavior is to attempt to extract the current running version of gitea
and only initiate the old behavior if the running version != `gitea_version`.
Default is old behavior due to the major logic change involved.
