fix the os version filter which cause problems

qemu/tests/cfg/qemu_guest_agent.cfg

 - qemu_guest_agent: install setup image_copy unattended_install.cdrom
     only Fedora, RHEL, Windows
-    no 8, 9, 10, 11, 12, 13, 14, 15
+    no Fedora.8, Fedora.9, Fedora.10, Fedora.11, Fedora.12, Fedora.13, Fedora.14, Fedora.15
     type = qemu_guest_agent
     gagent_name = "org.qemu.guest_agent.0"
     gagent_install_cmd = "rpm -q qemu-guest-agent || yum install -y qemu-guest-agent"