lib/uri/rfc2396_parser.rb (initialize): reduce bytecode size

Reduce the initialize method from 2088 to 1332 bytes on 32-bit x86
Measurement obtained using `memsize_of_all', as `memsize_of'
is non-recursive:

  a = ObjectSpace.memsize_of_all(RubyVM::InstructionSequence)
  RubyVM::InstructionSequence.compile(src)
  b = ObjectSpace.memsize_of_all(RubyVM::InstructionSequence)
  p(b - a)

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48292 b2dd03c8-39d4-4d8f-98ff-823fe69b080e