[18.09 backport] keep old network ids

[thaJeztah]

backport of moby#38580 for 18.09

for windows all networks are re-populated in the store during network controller initialization. In current version it also regenerate network Ids which may be referenced by other components and it may cause broken references to a networks. This commit avoids regeneration of network ids.

[thaJeztah]

Failure on PowerPC is unrelated, and should be fixed by #150 (I don't think a rebase is needed, as this PR only affects Windows)

21:31:40 breakoutError: "../victim/dotdot" is outside of "/tmp/docker-TestUntarInvalidFilenames681263291/dest"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestUntarInvalidHardlink637502400/victim/hello" -> "../victim/hello"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestUntarInvalidHardlink601277983/victim/hello" -> "/../victim/hello"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestUntarInvalidHardlink113006834/victim" -> "../victim"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestUntarInvalidHardlink161073065/victim" -> "../victim"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestUntarInvalidHardlink327472372/victim" -> "../victim"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestUntarInvalidHardlink988004803/victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestUntarInvalidSymlink846077510/dest/dotdot" -> "../victim/hello"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestUntarInvalidSymlink908380397/dest/slash-dotdot" -> "/../victim/hello"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestUntarInvalidSymlink341034856/dest/loophole-victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestUntarInvalidSymlink194043815/dest/loophole-victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestUntarInvalidSymlink412541146/dest/loophole-victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestUntarInvalidSymlink398698097/dest/loophole-victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestUntarInvalidSymlink171138332/dest/dir/loophole" -> "../../victim"
21:31:40 --- FAIL: TestTarUntarWithXattr (0.00s)
21:31:40 	archive_unix_test.go:236: assertion failed: error is not nil: invalid argument
21:31:40 breakoutError: "../victim/dotdot" is outside of "/tmp/docker-TestApplyLayerInvalidFilenames616906941/dest"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestApplyLayerInvalidHardlink502152695/victim/hello" -> "../victim/hello"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestApplyLayerInvalidHardlink517108458/victim/hello" -> "/../victim/hello"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestApplyLayerInvalidHardlink128068417/victim" -> "../victim"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestApplyLayerInvalidHardlink192443308/victim" -> "../victim"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestApplyLayerInvalidHardlink668817179/victim" -> "../victim"
21:31:40 breakoutError: invalid hardlink "/tmp/docker-TestApplyLayerInvalidHardlink650222014/victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestApplyLayerInvalidSymlink362502661/dest/dotdot" -> "../victim/hello"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestApplyLayerInvalidSymlink303792032/dest/slash-dotdot" -> "/../victim/hello"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestApplyLayerInvalidSymlink010907775/dest/loophole-victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestApplyLayerInvalidSymlink451325906/dest/loophole-victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestApplyLayerInvalidSymlink321944841/dest/loophole-victim" -> "../victim"
21:31:40 breakoutError: invalid symlink "/tmp/docker-TestApplyLayerInvalidSymlink554881748/dest/loophole-victim" -> "../victim"

[thaJeztah]

ping @ddebroy @fcrisciani @andrewhsu PTAL

[fcrisciani]

LGTM