447cbdd1d0
Saves 86 KB. And stop depending on expvar and usermetrics when disabled, in prep to removing all the expvar/metrics/tsweb stuff. Updates #12614 Change-Id: I35d2479ddd1d39b615bab32b1fa940ae8cbf9b11 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>