System added is not shown in the backend role edition

[rflorent]

Q	A
Bug?	yes
New Feature?	no
Sulu Version	1.5.3

Actual Behavior

The system added by the bundle is not shown in the select, when editing a role

Expected Behavior

The system should be shown in the select, to avoid loose it when editing a role

Steps to Reproduce

Install the bundle, init the bundle and edit a role

[alexander-schranz]

@danrot @chirimoya systems seems currently be hardcoded.

Solutions:

A. we query the database with SELECT system FROM se_roles GROUP BY system ORDER BY system for the select

B. we read the systems from the webspace manager to add them to the select