sos: collect /etc/rhevm

Due to a bug in sos /etc/rhevm was not collected.
This patch introduces a workaround by collecting its
content.

Change-Id: Iebee3f58a987921e7919a42810659f57cc96cae9
Bug-Url: https://bugzilla.redhat.com/1128738
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>