Description of problem:
There is wrong error message when user tries to configure an offset for all default port bindings. It says "Offset value is too large. Maximum offset possible is 0."

Version-Release number of selected component (if applicable):
 EAP 6.2.0.ER6

How reproducible:
 Always

Steps to Reproduce:
 1. Run console instalation: java -jar jboss-eap-6.2.0.ER6-installer.jar -console
 2. Follow:
Select Port Configuration:
0  [x] Use the default port bindings for standalone and domain modes.
1  [ ] Configure custom port bindings.
2  [ ] Configure an offset for all default port bindings.
Input Selection: 
2

Select Offset Type
0  [x] +1 offset
1  [ ] +100 offset
2  [ ] Specify offset
Input Selection: 
2
Offset value: []
1111

Actual results:
 Validation error.: Offset value is too large. Maximum offset possible is 0.

Expected results:
 Validation error.: Offset value is too large. Maximum offset possible is $MAXIMUM_OFFSET.