default gems: add missing comment in gemspec

* lib/csv/csv.gemspec: [DOC] add comment for require fallback
  in Ruby repository.

* lib/logger.gemspec: ditto.
* lib/prime.gemspec: ditto.
* lib/rexml/rexml.gemspec: ditto.
* lib/rss/rss.gemspec: ditto.
* lib/webrick/webrick.gemspec: ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65037 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/csv/csv.gemspec

@@ -3,6 +3,7 @@
 begin
   require_relative "lib/csv/version"
 rescue LoadError
+  # for Ruby core repository
   require_relative "version"
 end
 

lib/logger.gemspec

@@ -1,6 +1,7 @@
 begin
   require_relative "lib/logger"
 rescue LoadError
+  # for Ruby core repository
   require_relative "logger"
 end
 

lib/prime.gemspec

@@ -1,6 +1,7 @@
 begin
   require_relative "lib/prime"
 rescue LoadError
+  # for Ruby core repository
   require_relative "prime"
 end
 

lib/rexml/rexml.gemspec

@@ -1,6 +1,7 @@
 begin
   require_relative "lib/rexml/rexml"
 rescue LoadError
+  # for Ruby core repository
   require_relative "rexml"
 end
 

lib/rss/rss.gemspec

@@ -1,6 +1,7 @@
 begin
   require_relative "lib/rss"
 rescue LoadError
+  # for Ruby core repository
   require_relative "rss"
 end
 

lib/webrick/webrick.gemspec

@@ -2,6 +2,7 @@
 begin
   require_relative 'lib/webrick/version'
 rescue LoadError
+  # for Ruby core repository
   require_relative 'version'
 end