Make puma bind address configurable with BIND env var (mastodon#11326)

Author: zunda

config/puma.rb

@@ -4,7 +4,7 @@
 if ENV['SOCKET']
   bind "unix://#{ENV['SOCKET']}"
 else
-  bind "tcp://127.0.0.1:#{ENV.fetch('PORT', 3000)}"
+  bind "tcp://#{ENV.fetch('BIND', '127.0.0.1')}:#{ENV.fetch('PORT', 3000)}"
 end
 
 environment ENV.fetch('RAILS_ENV') { 'development' }