Fix rubyio.h include for Ruby 1.9
Fix rubyio.h include for Ruby 1.9

openSUSE/sat-solver-bindings,openSUSE/sat-solver-bindings,openSUSE/sat-solver-bindings,openSUSE/sat-solver-bindings,openSUSE/sat-solver-bindings,openSUSE/sat-solver-bindings