client/web: skip check mode for non-tailscale.com control servers
Only enforce check mode if the control server URL ends in
".tailscale.com". This allows the web client to be used with headscale
(or other) control servers while we work with the project to add check
mode support (tracked in juanfont/headscale#1623).
Updates #10261
Co-authored-by: Sonia Appasamy <sonia@tailscale.com>
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
Signed-off-by: Will Norris <will@tailscale.com>