Description of problem:
If you try to add sunbet for the External network when the value for sunbet value is incorrect (for example 10.10.299.0/27) the error message is complaining on format xxx.xxx.xxx.xxx/xx and not on incorrect value of the fields

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Import or create an External network in RHEV
2. Create Sunbet for that network
3. Fill in incorrect value for subnet and push ok button

Actual results:
An error message "This field must contain a CIDR in format xxx.xxx.xxx.xxx/yy"" is displayed

Expected results:
The message should explain the reason for the failure - incorrect value for subnet field for example

Additional info: