b9ebee1490 fix a couple things to make Elements 22's linter happy (Andrew Poelstra)
Pull request description:
In Elements 22 the linter looks for executable files that don't have a properly-formed shebang. For some reason it wants `/usr/bin/env bash` rather than `/bin/bash`, and also one of our source files was erroneously 755.
ACKs for top commit:
real-or-random:
ACK b9ebee1490
Tree-SHA512: 00da8fefd67c1882c6cec39dc81ce67ae3f52f902ddf72545e902b8f5bc7cd7c1249bf71027c530245c403a99c86ffbb61a89bc18c27c5ec975f6f653200766c