Refs #3002 -- clearly document that OpenSSL 1.0 support will be removed in the next release. (#3113)

diff --git a/docs/installation.rst b/docs/installation.rst
index 3d10c36..330817c 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -38,7 +38,7 @@
 
 .. warning::
     OpenSSL 1.0.0 is no longer supported by the OpenSSL project. Cryptography
-    will drop support for it in a future release.
+    will drop support for it in the next release.
 
 On Windows
 ----------