add_custom_target uninstall causes a clash with the same target in rtmidi (https://github.com/thestk/rtmidi).
"add_custom_target cannot create target "uninstall" because another target with the same name already exists. The existing target is a custom target created in source directory"
Adds new option YAML_CPP_DISABLE_UNINSTALL
fixes#1151
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Co-authored-by: Megamouse <studienricky89@googlemail.de>
Co-authored-by: Jesse Beder <jbeder+github@gmail.com>