ovirt-node-plugin-vdsm.spec: remove clean section

The %clean section is not required for F-13 and above.
Each package for F-12 and below (or EPEL 5) MUST have a %clean section

https://fedoraproject.org/wiki/Packaging:Guidelines?rd=Packaging/Guidelines#.25clean

Change-Id: Ica19bccd8fc205b1b632eabe653cfbf1dffe404f
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
SPEC: Add BuildRequires:  python2-devel

For python packages is required to add BuildRequires
https://fedoraproject.org/wiki/Packaging:Python#BuildRequires

Change-Id: I15929a8f7e66d1738c378016f8cacfacbef1208c
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>