guix-install.sh: Avoid "#!/bin/bash" shebang....Fixes <https://bugs.gnu.org/34279>.
Reported by Claes Wallin (韋嘉誠) <clacke@lysator.liu.se>.
* etc/guix-install.sh: Change shebang to #!/bin/sh and add 'if'
statement to spawn Bash if needed.
Ludovic Courtès
2018-12-13
guix-install.sh: Use pool.sks-keyservers.net...."pgp.mit.edu" has been unavailable for some time.
* etc/guix-install.sh (chk_require): Change key server to
pool.sks-keyservers.net.