[rubygems/rubygems] Move require uri to source_list

https://github.com/rubygems/rubygems/commit/c6b4df5bfc

lib/rubygems/source.rb

@@ -28,7 +28,6 @@ class Gem::Source
   # Creates a new Source which will use the index located at +uri+.
 
   def initialize(uri)
-    require "uri"
     begin
       unless uri.kind_of? URI
         uri = URI.parse(uri.to_s)

lib/rubygems/source_list.rb

@@ -50,6 +50,8 @@ class Gem::SourceList
   # String.
 
   def <<(obj)
+    require "uri"
+
     src = case obj
           when URI
             Gem::Source.new(obj)