Remove reference to deleted file
Remove reference to deleted file

injected.js was deleted in a previous commit, but the manifest still references it.
gdh1995/vimium,gdh1995/vimium,smblott-github/vimium,philc/vimium,philc/vimium,smblott-github/vimium,smblott-github/vimium,philc/vimium,gdh1995/vimium