remote_update_cache=false unintentionally disables remote cache reads (remote_accept_cache has no effect)

[randyli]

Setting --remote_update_cache=false on rewrapper is supposed to prevent writing results to the remote cache while still accepting cache hits. In practice, it also disables remote cache reads, making --remote_accept_cache=true have no effect.

Steps to reproduce

rewrapper \
--remote_accept_cache=true \
--remote_update_cache=false \
--

Expected: cache hits are returned for previously cached actions.
Actual: every action executes as a cache miss, even when a valid cached result exists.