Revert "change icons to version with 7 images"

This reverts commit 08dfa3ab81aaa5d8e519479954d3571464548177.
Merge pull request #573 from langerhans/1.7.2-revert-ico

Revert "change icons to version with 7 images"
Fix expected SHA256 hashes for dependencies in release-process.md

Because we use a different bdb version than bitcoin, SHA256 of
dogecoin-deps-* gitian built files are different. New hashes
match both langerhans' 1.7.2-Beta-1 committed sigs at
https://github.com/dogecoin/gitian.sigs and my own.
Merge pull request #575 from patricklodder/1.7.2-dev-gitian-dep-sigs

[minor] Fix expected SHA256 hashes for dogecoin-deps-*