Hide to instance variable not initialized waring

[S-H-GAMELINKS]

I tried bundle exec rake test in Ruby 2.7(check in 2.7.0, 2.7.1, 2.7.2), and shown this warning.

/home/sh/rubydev/typeprof/lib/typeprof/analyzer.rb:496: warning: instance variable @namespace not initialized

@namespace instance variable initialized code added, and hide to this warning.

[mame]

Thank you!