Can't use murano plugin in fuel dashboard

[Pavel]

Detailed bug description:
Problem discovered on MOS 9.0 #632 with Murano plugin 1.2

Steps to reproduce:
 Deploy MOS 9.0 #632, install Murano plugin, try to install smth from "Application Catalog" in Openstack "Dashboard"
Expected results:
 Application installed.
Actual result:
 Got tooltip: "Danger: There was an error submitting the form. Please try again." and nothigs was installed.
Reproducibility:
 100%
Workaround:
 n/a
Impact:
 unknown
Description of the environment:
 * 5 virt nodes:
    - CPU: 5(16) x 2.10 GHz
    - Disks: 128x5 virtual disks, 640Gb total
    - Memory: 5+5+5+3+3 = 21.0 GB total
    - NUMA topology: 1 NUMA node
 * Node roles:
   - 1 controllers
   - 4 computes
 * Details:
   - OS on controllers: Mitaka on Ubuntu 14.04
   - OS on computes: RHEL
   - Compute: KVM
   - Neutron with VLAN segmentation
   - Storage Backends: Cinder LVM over iSCSI for volumes