Ruby

test_process.rb: fix error when empty groups

• test/ruby/test_process.rb (test_maxgroups): set one element at
  least get rid of ZeroDivisionError when no process groups.
  [ruby-core:84224] [Bug #14174]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61206 b2dd03c8-39d4-4d8f-98ff-823fe69b080e