Update Ruby upgrade instructions for 11.0

doc/update/10.8-to-11.0.md

@@ -31,7 +31,7 @@ sudo -u git -H bundle exec rake gitlab:backup:create RAILS_ENV=production
 
 ### 3. Update Ruby
 
-NOTE: GitLab 9.0 and higher only support Ruby 2.3.x and dropped support for Ruby 2.1.x. Be
+NOTE: GitLab 11.0 and higher only support Ruby 2.4.x and dropped support for Ruby 2.3.x. Be
 sure to upgrade your interpreter if necessary.
 
 You can check which version you are running with `ruby -v`.
@@ -40,9 +40,9 @@ Download Ruby and compile it:
 
   ```bash
     mkdir /tmp/ruby && cd /tmp/ruby
-    curl --remote-name --progress https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.7.tar.gz
-    echo '540996fec64984ab6099e34d2f5820b14904f15a  ruby-2.3.7.tar.gz' | shasum -c - && tar xzf ruby-2.3.7.tar.gz
-    cd ruby-2.3.7
+    curl --remote-name --progress https://cache.ruby-lang.org/pub/ruby/2.4/ruby-2.4.4.tar.gz
+    echo 'ec82b0d53bd0adad9b19e6b45e44d54e9ec3f10c  ruby-2.4.4.tar.gz' | shasum -c - && tar xzf ruby-2.4.4.tar.gz
+    cd ruby-2.4.4
 
     ./configure --disable-install-rdoc
     make