ShaderPlug binding : Add default value for `_copy` argument
ShaderPlug binding : Add default value for `_copy` argument

appleseedhq/gaffer,hradec/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,lucienfostier/gaffer,boberfly/gaffer,andrewkaufman/gaffer,appleseedhq/gaffer,lucienfostier/gaffer,ImageEngine/gaffer,andrewkaufman/gaffer,hradec/gaffer,boberfly/gaffer,johnhaddon/gaffer,hradec/gaffer,boberfly/gaffer,johnhaddon/gaffer,hradec/gaffer,andrewkaufman/gaffer,andrewkaufman/gaffer,GafferHQ/gaffer,appleseedhq/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,ImageEngine/gaffer,boberfly/gaffer,lucienfostier/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,hradec/gaffer,GafferHQ/gaffer,lucienfostier/gaffer