Merge JoinMarket-Org/joinmarket-clientserver#1361: Allow to run `install.sh` from any current working directory

e47f0823cb Allow to run install.sh from any current working directory (Kristaps Kaupe)

Pull request description:

  Person [porting JoinMarket guide from RaspiBolt v2 to RaspiBolt v3](https://github.com/raspibolt/raspibolt/pull/1085) tried to do `./joinmarket/install.sh` instead of `cd joinmarket; ./install.sh`, but that ends in GPG validation error, because third-party pubkeys are imported using relative paths. Don't see the reason why not allow to run `install.sh` from any cwd.

Top commit has no ACKs.

Tree-SHA512: daf0cfabb2c5048c58664812e259b65d4ee838c5d3f3f37939713d74d0d73054cf08fe7fb49e8b184c223105c9d3a71592bcaa4376d32e45046c372614a3a76c

install.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+cd "$(dirname "$0")"
+
 check_exists() {
     command -v "$1" > /dev/null
 }