remove trailing spaces

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36681 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

sample/README

@@ -23,7 +23,7 @@ less.rb		front end for less
 list.rb		stupid object sample
 list2.rb	stupid object sample
 list3.rb	stupid object sample
-mine.rb		simple mine sweeper	
+mine.rb		simple mine sweeper
 mkproto.rb	extract prototype from C
 mpart.rb	split file int multi part
 observ.rb	observer design pattern sample