proc.c: [DOC] fix grammar in doc for Method#to_s
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65378 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
proc.c: [DOC] fix grammar in doc for Method#to_s
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65378 b2dd03c8-39d4-4d8f-98ff-823fe69b080e