packaging: engine-setup - Improve ear and pgsql_ds links creation proccess
packaging: engine-setup - Improve ear and pgsql_ds links creation proccess

Add existence check before creating symlinks inside JBoss.

Change-Id: Ie0aaa3f4073b0c6cd52829b64357a540961ea505
Acked-by: Eyal Edri <0c20e4549535c289cc2166cc92c7b892ceb19f3b@redhat.com>

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