protocol: fix spurious rejection of downloaded blocks

when kicking a peer for inactivity, clear the set of requested blocks,
or next time we requests blocks from it, we'll probably reject the
incoming blocks due to missing the previous requested blocks

src/cryptonote_protocol/cryptonote_protocol_handler.inl

@@ -153,6 +153,7 @@ namespace cryptonote
             context.m_last_request_time = boost::date_time::not_a_date_time;
             context.m_expect_response = 0;
             context.m_expect_height = 0;
+            context.m_requested_objects.clear();
             context.m_state = cryptonote_connection_context::state_standby; // we'll go back to adding, then (if we can't), download
           }
           else