Remove deprecation warming by switching from URI::DEFAULT_PARSER to U…

…RI::RFC2396_PARSER

lib/rack/utf8_sanitizer.rb

@@ -256,7 +256,7 @@ def unescape_unreserved(input)
     # Performs the reverse function of `unescape_unreserved`. Unlike
     # the previous function, we can reuse the logic in URI#encode
     def escape_unreserved(input)
-      URI::DEFAULT_PARSER.escape(input, UNSAFE)
+      URI::RFC2396_PARSER.escape(input, UNSAFE)
     end
 
     def sanitize_string(input)