[ruby/uri] Removed duplicated declare step for constants under the URI::RFC2396_REGEXP::PATTERN

https://github.com/ruby/uri/commit/60a8bc1575

lib/uri/common.rb

@@ -31,11 +31,6 @@ module URI
     if Parser == RFC2396_Parser
       const_set("REGEXP", URI::RFC2396_REGEXP)
       const_set("PATTERN", URI::RFC2396_REGEXP::PATTERN)
-      Parser.new.pattern.each_pair do |sym, str|
-        unless REGEXP::PATTERN.const_defined?(sym)
-          REGEXP::PATTERN.const_set(sym, str)
-        end
-      end
     end
 
     Parser.new.regexp.each_pair do |sym, str|

test/uri/test_common.rb

@@ -40,6 +40,7 @@ class URI::TestCommon < Test::Unit::TestCase
     assert defined?(URI::REGEXP)
     assert defined?(URI::PATTERN)
     assert defined?(URI::PATTERN::ESCAPED)
+    assert defined?(URI::REGEXP::PATTERN::IPV6ADDR)
 
     URI.parser = URI::RFC3986_PARSER