debian/patches/git-updates.diff: update from upstream stable branch:

* debian/patches/git-updates.diff: update from upstream stable branch:
  - Fix a data corruption in SSE2-optimized memmove implementation for
    i386 (CVE-2017-18269).
  - Fix a stack-based buffer overflow in the realpath function
    (CVE-2018-11236).  Closes: #899071.
  - Fix a buffer overflow in the AVX-512-optimized implementation of the
    mempcpy function (CVE-2018-11237).  Closes: #899070.