package/lz4: security bump to version 1.9.2

package/lz4: security bump to version 1.9.2

- Fix CVE-2019-17543: LZ4 before 1.9.2 has a heap-based buffer overflow
  in LZ4_write32 (related to LZ4_compress_destSize), affecting
  applications that call LZ4_compress_fast with a large input. (This
  issue can also lead to data corruption.) NOTE: the vendor states "only
  a few specific / uncommon usages of the API are at risk."
- Update indentation of hash file (two spaces)

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>