LU-11518 ptlrpc: don't reset lru_resize on idle reconnect

LU-11518 ptlrpc: don't reset lru_resize on idle reconnect

ptlrpc_disconnect_idle_interpret() clears imp_remote_handle,
so reconnect has pcaa_initial_connect set to 1.

Update only changed ns_connect_flags bits.

Fixes: 5a6ceb664f0 ("LU-7236 ptlrpc: idle connections can disconnect")

Lustre-change: https://review.whamcloud.com/35285
Lustre-commit: acacc9d9b1d0a869f61d7940baa0700b63dcd8f7

Change-Id: I2368708b6381c1d772c47dc6e61c8fb39a14a2cc
Cray-bug-id: LUS-7471
Signed-off-by: Andriy Skulysh <c17819@cray.com>
Reviewed-by: Alexander Boyko <c17825@cray.com>
Reviewed-by: Andrew Perepechko <c17827@cray.com>
Reviewed-by: Alexandr Boyko <c17825@cray.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Gu Zheng <gzheng@ddn.com>
Signed-off-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/35489
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>