net-im/mastodon: Fix run-time issues by updating dependencies

• Depend on textproc/rubygem-twitter-text1 to fix a run-time error after textproc/rubygem-twitter-text was upgraded to a version unsupported by Mastodon.

• After r457876, 457885, and r457886, net-im/mastodon failed to start, because of an issue with both versions 3 and 4 of the redis gem being pulled in.
  
  /usr/local/lib/ruby/gems/2.4/gems/bundler-1.16.1/lib/bundler/runtime.rb:313:in `check_for_activated_spec!': You have already activated redis 4.0.1, but your Gemfile requires redis 3.3.5.
  
  Patch, so that only version 4 is pulled in.