Disable stringio >= 0.1.3 dependency

If we have it, we can use the csv gem with a Rack application on
Passenger.

Author: kou

csv.gemspec

@@ -48,7 +48,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = ">= 2.5.0"
 
-  spec.add_dependency "stringio", ">= 0.1.3"
+  # spec.add_dependency "stringio", ">= 0.1.3"
   spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "benchmark_driver"