Use more complete regexp

https://github.com/basecamp/fizzy/pull/564/files#r2119855866

app/helpers/html_helper.rb

@@ -9,7 +9,7 @@ module HtmlHelper
 
   private
     EXCLUDED_ELEMENTS = %w[ a figcaption pre code ]
-    EMAIL_REGEXP = /\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}\b/
+    EMAIL_REGEXP = /\b[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*\b/
     URL_REGEXP = URI::DEFAULT_PARSER.make_regexp(%w[http https])
 
     def auto_link(fragment)