test/test_weakref.rb: increase timeout [Bug #10618]

* test/test_weakref.rb (test_repeated_object_leak): increase timeout
  [Bug #10618]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48900 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-12-20

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48901 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ChangeLog: fixup r48900

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48902 b2dd03c8-39d4-4d8f-98ff-823fe69b080e