Please give back julia on arm64

[Graham Inggs]

Hi Wanna Build Team

The build of julia 0.4.7-5 failed on arm64.  This was unexpected as 
there should have been no code changes affecting arm64.
I have confirmed that 0.4.7-5 builds successfully on asachi.debian.org.
gb julia_0.4.7-5 . arm64

Regards
Graham