beep: change git repository to fix CVE-2018-0492 and CVE-2018-1000532

beep: change git repository to fix CVE-2018-0492 and CVE-2018-1000532

1. Changed Git repository, which is used for Fedora packaging
https://github.com/johnath/beep/issues/11#issuecomment-450277122

Fixed CVEs:
CVE-2018-0492 - https://nvd.nist.gov/vuln/detail/CVE-2018-0492
CVE-2018-1000532 - https://nvd.nist.gov/vuln/detail/CVE-2018-1000532

2. Fixed SPDX License Identifier

3. Add patch to comment out -D_FORTIFY_SOURCE
Otherwise, it can not be built by default.

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>