Incorrect description of the bitstream read role community/collection edit forms

[mspalti]

Describe the bug

In i18n files,comcol-role.edit.bitstream_read.description is identical to comcol-role.edit.community-admin.description

Both are translated as follows: "Community administrators can create sub-communities or collections, and manage or assign management for those sub-communities or collections. In addition, they decide who can submit items to any sub-collections, edit item metadata (after submission), and add (map) existing items from other collections (subject to authorization)."

Expected behavior
The bitstream_read description should probably be something like :
"E-People and Groups that can read new bitstreams submitted to this collection. Changes to this role are not retroactive."

[tdonohue]

@mspalti : You're right! I see that on the demo site too now that I look more closely. Please feel free to send a small PR and I can get it reviewed/merged immediately (into both 7.x and pre-8.0)