[ui] JScript validation red box alert about network intersection

[Alexander Kurenyshev]

There is no red box alert when floating ip's range intersect with public one.

Steps to reproduce:

1) Create new cluster
2) Go to Network Settings
3) Fill with valid values Public IP network range
4) Enter a value for start bound of floating network ip range the same as the end bound of Public.

Expected result:

There is the red box alert on the right side that says about IP range intersection.

Actual result:

There is no any notification.