EventuallyPersistentEngine persists ep_force_shutdown=false before the flushers have been shutdown

guides/gradlew --refresh-dependencies testrunner -P jython=/opt/jython/bin/jython -P 'args=-i /tmp/testexec.100827.ini -p bucket_storage=magma,rerun=false,GROUP=P0;durability,randomize_value=true,doc_size=256,bucket_eviction_policy=fullEviction,nodes_init=4,graceful=False,dcp_services=n1ql:index,enable_dp=True,get-cbcollect-info=True,upgrade_version=7.0.0-4960 -t magma.magma_crash_recovery.MagmaCrashTests.test_crash_during_ops,doc_size=256,upgrade_version=7.0.0-4960,graceful=False,rerun=false,GROUP=P0;durability,enable_dp=True,doc_ops=create:update:delete:expiry,sdk_timeout=60,dcp_services=n1ql:index,get-cbcollect-info=True,replicas=1,durability=MAJORITY,bucket_storage=magma,log_level=error,bucket_eviction_policy=fullEviction,nodes_init=4,num_items=5000000,randomize_value=true,infra_log_level=critical'

['2021-04-18T22:40:18.482632-07:00 ERROR 6601: (default) DCP (Producer) eq_dcpq:replication:ns_1@172.23.106.163->ns_1@172.23.106.164:default - DcpProducer::handleResponse disconnecting, received unexpected response:{"bodylen":0,"cas":0,"datatype":"raw","extlen":0,"keylen":0,"magic":"ClientResponse","opaque":18,"opcode":"DCP_COMMIT","status":"Not found"} for stream:stream name:eq_dcpq:replication:ns_1@172.23.106.163->ns_1@172.23.106.164:default, vb:357, state:in-memory\n']