Update stringio.gemspec

Co-authored-by: Sutou Kouhei <[email protected]>

Author: mark-young-atg

stringio.gemspec

@@ -39,7 +39,7 @@ Gem::Specification.new do |s|
   s.required_ruby_version = ">= 2.7"
   s.summary = "Pseudo IO on String"
 
-  s.metadata["changelog_uri"] = s.homepage + "/blob/master/NEWS.md"
+  s.metadata["changelog_uri"] = "#{s.homepage}/releases/tag/v#{s.version}"
 
   # s.cert_chain  = %w[certs/nobu.pem]
   # s.signing_key = File.expand_path("~/.ssh/gem-private_key.pem") if $0 =~ /gem\z/