Use a universal shebang

apps/files_external/tests/env/start-amazons3-ceph.sh

apps/files_external/tests/env/start-ftp-morrisjobke.sh

apps/files_external/tests/env/start-sftp-atmoz.sh

apps/files_external/tests/env/start-smb-silvershell.sh

apps/files_external/tests/env/start-smb-windows.sh

apps/files_external/tests/env/start-webdav-ownCloud.sh

apps/files_external/tests/env/stop-amazons3-ceph.sh

apps/files_external/tests/env/stop-ftp-morrisjobke.sh

apps/files_external/tests/env/stop-sftp-atmoz.sh

apps/files_external/tests/env/stop-smb-silvershell.sh

apps/files_external/tests/env/stop-smb-windows.sh

apps/files_external/tests/env/stop-webdav-ownCloud.sh

autotest-external.sh

autotest-js.sh

autotest.sh

buildjsdocs.sh

core/img/image-optimization.sh

l10n/rm-old.sh