bug 948151: Add attachment URLs to CSP img-src
bug 948151: Add attachment URLs to CSP img-src

Add the production attachment URL to the list of CSP allowed domains for
images (img-src). Include the local attachment URL if it isn't
production or the same as the web domain (covered by 'self').

escattone/kuma,a2sheppy/kuma,Elchi3/kuma,jwhitlock/kuma,jwhitlock/kuma,a2sheppy/kuma,escattone/kuma,mozilla/kuma,jwhitlock/kuma,SphinxKnight/kuma,a2sheppy/kuma,Elchi3/kuma,SphinxKnight/kuma,SphinxKnight/kuma,Elchi3/kuma,jwhitlock/kuma,Elchi3/kuma,SphinxKnight/kuma,SphinxKnight/kuma,a2sheppy/kuma,mozilla/kuma,mozilla/kuma,mozilla/kuma,jwhitlock/kuma,mozilla/kuma,a2sheppy/kuma,SphinxKnight/kuma,escattone/kuma,Elchi3/kuma