tools: engine-setup - Fixed memory requirements
tools: engine-setup - Fixed memory requirements

for running the engine, 4Gb is the minimum,
16Gb is the recomended ammount of RAM.

Change-Id: I4f439d41d76497cf5a69224ce257881d4ed23087
Bug-Url: https://bugzilla.redhat.com/921079
Signed-off-by: Sandro Bonazzola <fcb014d63786651910af5db2ecc5316c668188ef@redhat.com>

eayun/ovirt-engine,eayun/ovirt-engine,halober/ovirt-engine,yapengsong/ovirt-engine,walteryang47/ovirt-engine,yapengsong/ovirt-engine,OpenUniversity/ovirt-engine,yingyun001/ovirt-engine,yapengsong/ovirt-engine,OpenUniversity/ovirt-engine,yapengsong/ovirt-engine,yapengsong/ovirt-engine,eayun/ovirt-engine,eayun/ovirt-engine,yingyun001/ovirt-engine,walteryang47/ovirt-engine,zerodengxinchao/ovirt-engine,zerodengxinchao/ovirt-engine,zerodengxinchao/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,halober/ovirt-engine,walteryang47/ovirt-engine,OpenUniversity/ovirt-engine,eayun/ovirt-engine,walteryang47/ovirt-engine,halober/ovirt-engine,walteryang47/ovirt-engine,yingyun001/ovirt-engine,yingyun001/ovirt-engine,zerodengxinchao/ovirt-engine,halober/ovirt-engine,yingyun001/ovirt-engine,OpenUniversity/ovirt-engine