Ignore errors in supplementary group setup during app launch preparation

Ignore errors in supplementary group setup during app launch preparation

Such errors might happen when launcher tries to launch an application that
wasn't properly setup by the installer before. This should be supported to
allow easier integration of security-manager into platform.
Ignoring these errors won't cause any privilege escalation. Actually it
might cause giving less privileges than necessary to the application.

Change-Id: Ib8ba02a28404a25c541ba6daede9f68c864583cc
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>