Update core/encoding/default_external_spec.rb

Author: eregon

core/encoding/default_external_spec.rb

@@ -20,7 +20,7 @@
 
   ruby_version_is "3.0" do
     platform_is :windows do
-      it 'returns default external encoding for Windows' do
+      it 'is UTF-8 by default on Windows' do
         Encoding.default_external.should == Encoding::UTF_8
       end
     end