CHERRY-PICK: date-proxy-watcher: fix regex to accept "-" in host names

Handling of grep's [] characters must have "-" as the first or last
character to be understood as a literal.

BUG=chromium:278618
TEST=stout build, proxy with "-" in name can be used.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/167571
Reviewed-by: Will Drewry <wad@chromium.org>

Change-Id: I244010cc48cefd5588b0352d0be8ea7129710ae1
(cherry picked from ToT commit 5efb136c0a273f4a41d5f05a70009d379cb13110)
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/168085
Reviewed-by: Will Drewry <wad@chromium.org>
1 file changed