webadmin: Small fix for removing profiles

As part of a very recent large refactoring, some regression was
introduced in the add/remove profiles widget in the edit network
dialog, that disregarded removal of profiles. This patch fixes it.

Change-Id: Iea8aa1b670dc12109da30549ab61975215e0c174
Signed-off-by: Lior Vernia <lvernia@redhat.com>