Fix Requester's storage pipeline not returning to issuing new commands

after pausing because too many were in flight

yama/src/remote/requester.rs

@@ -401,6 +401,7 @@ impl RawPile for Requester {
                         // Either the pipeline is stopping or we are too busy to accept new chunks,
                         // so only process responses.
                         let resp = response_rx.recv().unwrap();
+                        in_flight_writes -= 1;
                         match resp {
                             ResponseBody::Success => {
                                 // nop