better error when trying to enroll an untrusted url

[dovholuknf]

With the new enrollment by url option, when supplying a URL that is not pre-trusted by the OS's trust store, ZITI_ENROLLMENT_METHOD_UNSUPPORTED is returned but it should be a better error in that situation. It's not the enrollment method, it's the lack of pre-configured trust that causes the problem

[2024-12-17T13:20:08.092Z]    INFO ziti-edge-tunnel:process_cmd.c:125 enroll_ziti_async() enrollment started. identity file will be written to: c:\windows\system32\config\systemprofile\appdata\roaming\netfoundry\ctrl.cdaws.clint.demo.openziti.org_8441.json
[2024-12-17T13:20:08.199Z]    WARN ziti-sdk:ziti_ctrl.c:183 ctrl_resp_cb() ctrl[ctrl.cdaws.clint.demo.openziti.org:8441] request failed: -4079(software caused connection abort)
[2024-12-17T13:20:08.199Z]    WARN ziti-sdk:ziti_ctrl.c:323 internal_version_cb() ctrl[ctrl.cdaws.clint.demo.openziti.org:8441] CONTROLLER_UNAVAILABLE(software caused connection abort)
[2024-12-17T13:20:08.199Z]    WARN ziti-sdk:ziti_ctrl.c:183 ctrl_resp_cb() ctrl[ctrl.cdaws.clint.demo.openziti.org:8441] request failed: -4079(software caused connection abort)
[2024-12-17T13:20:08.199Z]    INFO ziti-sdk:ziti_ctrl.c:186 ctrl_resp_cb() ctrl[ctrl.cdaws.clint.demo.openziti.org:8441] attempting to switch endpoint
[2024-12-17T13:20:08.199Z]    WARN ziti-sdk:ziti_ctrl.c:579 ctrl_next_ep() ctrl[ctrl.cdaws.clint.demo.openziti.org:8441] no controllers are online
[2024-12-17T13:20:08.200Z]   ERROR ziti-edge-tunnel:process_cmd.c:60 tunnel_enroll_cb() enrollment failed: unsupported enrollment method(-8)