Update en_US.lang
Update en_US.lang

Just a quick addition of a backspace.
pixlepix/Aura-Cascade,DaedalusGame/Aura-Cascade,Mazdallier/Aura-Cascade,Vazkii/Aura-Cascade,DaedalusGame/Aura-Cascade,Vazkii/Aura-Cascade,pixlepix/Aura-Cascade,Mazdallier/Aura-Cascade