include_subnets flag does not exist

[D Ray]

The Murano app-dev guide documents the dynamic ui components in:
https://docs.openstack.org/murano/latest/admin/appdev-guide/muranopackages/dynamic_ui.html

The Forms section documents the include_subnets flag as follows:
include_subnets is used only with network field. True by default. If True, the field list includes all the possible combinations of network and subnet. E.g. if there are two available networks X and Y, and X has two subnets A and B, while Y has a single subnet C, then the list will include 3 items: (X, A), (X, B), (Y, C). If set to False only network names will be listed, without their subnets.

It appears that this flag was removed with the integration of:
https://review.openstack.org/#/c/481068/

Either the documentation should be updated to reflect the removal, or the flag should be re-introduced in the code.

(OpenStack Pike)