Revert "Add missing include."
Revert "Add missing include."

Reason: broken build.

This reverts commit 0d810ad6d5dca43965cdfa3a41a979e0a4a5a301.

dand-oss/yaml-cpp,kn65op/yaml-cpp,tangrams/yaml-cpp,graehl/yaml-cpp,WaveBlocks/yaml-cpp,tangrams/yaml-cpp,WaveBlocks/yaml-cpp,butataatawa/yaml-cpp,SimplyKnownAsG/yaml-cpp,ysyrov/yaml-cpp,kn65op/yaml-cpp,loot/yaml-cpp,butataatawa/yaml-cpp,jbeder/yaml-cpp,tangrams/yaml-cpp,SimplyKnownAsG/yaml-cpp,dand-oss/yaml-cpp,ysyrov/yaml-cpp,Mightyjo/yaml-cpp,WaveBlocks/yaml-cpp,jbeder/yaml-cpp,kn65op/yaml-cpp,graehl/yaml-cpp,loot/yaml-cpp,WrinklyNinja/yaml-cpp,dand-oss/yaml-cpp,graehl/yaml-cpp,ysyrov/yaml-cpp,SimplyKnownAsG/yaml-cpp,loot/yaml-cpp,ysyrov/yaml-cpp,WaveBlocks/yaml-cpp,jbeder/yaml-cpp,WrinklyNinja/yaml-cpp,jbeder/yaml-cpp,WrinklyNinja/yaml-cpp,butataatawa/yaml-cpp,tangrams/yaml-cpp,Mightyjo/yaml-cpp,Mightyjo/yaml-cpp,graehl/yaml-cpp,SimplyKnownAsG/yaml-cpp,dand-oss/yaml-cpp,loot/yaml-cpp,Mightyjo/yaml-cpp,graehl/yaml-cpp,jbeder/yaml-cpp,WrinklyNinja/yaml-cpp,kn65op/yaml-cpp,butataatawa/yaml-cpp,dand-oss/yaml-cpp