packaging: spec: Handle existing links on install
packaging: spec: Handle existing links on install

Since JBoss 7 doesn't support symlinks yet, the rpm post section must
remove existing link so host installation will work

Change-Id: I334499ebc5cdf1b2edb64d5a3ca74154534ffbe1

yingyun001/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,yapengsong/ovirt-engine,derekhiggins/ovirt-engine,eayun/ovirt-engine,derekhiggins/ovirt-engine,Dhandapani/gluster-ovirt,yingyun001/ovirt-engine,eayun/ovirt-engine,raksha-rao/gluster-ovirt,Dhandapani/gluster-ovirt,yingyun001/ovirt-engine,zerodengxinchao/ovirt-engine,Dhandapani/gluster-ovirt,yapengsong/ovirt-engine,derekhiggins/ovirt-engine,halober/ovirt-engine,raksha-rao/gluster-ovirt,walteryang47/ovirt-engine,yapengsong/ovirt-engine,yingyun001/ovirt-engine,OpenUniversity/ovirt-engine,raksha-rao/gluster-ovirt,raksha-rao/gluster-ovirt,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,halober/ovirt-engine,walteryang47/ovirt-engine,eayun/ovirt-engine,raksha-rao/gluster-ovirt,eayun/ovirt-engine,eayun/ovirt-engine,yingyun001/ovirt-engine,yapengsong/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,OpenUniversity/ovirt-engine,zerodengxinchao/ovirt-engine,Dhandapani/gluster-ovirt,walteryang47/ovirt-engine,walteryang47/ovirt-engine,derekhiggins/ovirt-engine,halober/ovirt-engine,walteryang47/ovirt-engine,Dhandapani/gluster-ovirt,halober/ovirt-engine,yapengsong/ovirt-engine