Fixes #4683 -- fixed linux kernel version that has getrandom (#4684)

diff --git a/docs/hazmat/backends/openssl.rst b/docs/hazmat/backends/openssl.rst
index 52aeeaf..07ae74a 100644
--- a/docs/hazmat/backends/openssl.rst
+++ b/docs/hazmat/backends/openssl.rst
@@ -106,7 +106,7 @@
 +------------------------------------------+------------------------------+
 | Windows                                  | ``CryptGenRandom()``         |
 +------------------------------------------+------------------------------+
-| Linux >= 3.4.17 with working             | ``getrandom(GRND_NONBLOCK)`` |
+| Linux >= 3.17 with working               | ``getrandom(GRND_NONBLOCK)`` |
 | ``SYS_getrandom`` syscall                |                              |
 +------------------------------------------+------------------------------+
 | OpenBSD >= 5.6                           | ``getentropy()``             |