rgw: clear bufferlist if write_data() successful

Fixes: #9201
Backport: firefly

We sometimes need to call RGWPutObjProcessor::handle_data() again,
so that we send the pending data. However, we failed to clear the buffer
that was already sent, thus it was resent. This triggers when using non
default pool alignments.

Signed-off-by: Yehuda Sadeh <yehuda@redhat.com>
rgw: convert header field underscores into dashes

Fixes: 9206
Backport: firefly

Certain web servers filter out underscores in the header field name.
Convert them into dashes.

Signed-off-by: Yehuda Sadeh <yehuda@redhat.com>
civetweb: update submodule

Fixes: #9208

Signed-off-by: Yehuda Sadeh <yehuda@redhat.com>
civetweb: update submodule

Add access log api

Signed-off-by: Yehuda Sadeh <yehuda@redhat.com>