lxc-alpine: remove all bashisms, make it compatible with dash
lxc-alpine: remove all bashisms, make it compatible with dash

Signed-off-by: Jakub Jirutka <1d3764b91b902f6b45836e2498da81fe35caf6d6@jirutka.cz>

akshaykarle/lxc,aeris/lxc,GreatFruitOmsk/lxc,hfuCN/lxc,caglar10ur/lxc,aeris/lxc,QingweiPeterLan/cs188-lxc,hallyn/lxc,caglar10ur/lxc,ysbnim/lxc,terceiro/lxc,hfuCN/lxc,federicobriata/lxc,hfuCN/lxc,LynxChaus/lxc,caglar10ur/lxc,ss1h2a3tw/lxc,akshaykarle/lxc,thmo/lxc,cjwatson/lxc,aeris/lxc,terceiro/lxc,ysbnim/lxc,ss1h2a3tw/lxc,QingweiPeterLan/cs188-lxc,thmo/lxc,cjwatson/lxc,ss1h2a3tw/lxc,federicobriata/lxc,GreatFruitOmsk/lxc,ysbnim/lxc,LynxChaus/lxc,akshaykarle/lxc,thmo/lxc,terceiro/lxc,LynxChaus/lxc,QingweiPeterLan/cs188-lxc,hallyn/lxc,GreatFruitOmsk/lxc,tych0/lxc,cjwatson/lxc,federicobriata/lxc,tych0/lxc,tych0/lxc,hallyn/lxc