[Subdoc] Timeouts on multipath ops

Future: <Task finished coro=<changeDocument() done, defined at /opt/python3.5/lib/python3.5/asyncio/coroutines.py:204> exception=_TimeoutError_0x17 (generated, catch TimeoutError)({'csrc_info': ('src/multiresult.c', 309), 'key': 'key9429', 'rc': 23, 'message': 'Operational Error'},)>

Traceback (most recent call last):

  File "/opt/python3.5/lib/python3.5/asyncio/tasks.py", line 239, in _step

    result = coro.send(None)

  File "/opt/python3.5/lib/python3.5/asyncio/coroutines.py", line 206, in coro

    res = func(*args, **kw)

  File "start-workload.py", line 40, in changeDocument

    rv = bucket.mutate_in(key, SD.addunique('array', '\"wo\/rld\"'))

  File "/root/couchbase-python-client/couchbase/bucket.py", line 929, in mutate_in

    return super(Bucket, self).mutate_in(key, specs, **kwargs)

couchbase.exceptions._TimeoutError_0x17 (generated, catch TimeoutError): <Key='key9429', RC=0x17[Client-Side timeout exceeded for operation. Inspect network conditions or increase the timeout], Operational Error, Results=1, C Source=(src/multiresult.c,309)>