Redmine

There is table which states that ruby 1.9.3 is compatible with redmine 3.4.
However 3.4.3 has in Gemfile:

gem "public_suffix", "~> 2.0.5" if RUBY_VERSION < "2.1" 

But

gem install public_suffix -v '2.0.5'
ERROR:  Error installing public_suffix:
        public_suffix requires Ruby version >= 2.0.

So 3.4.3 is no longer works with Ruby 1.9.3 or is it possible to use older version of this gem with support of Ruby 1.9.3?