fixed template ambiguity revealed in gcc4.8
fixed template ambiguity revealed in gcc4.8

NeoGeographyToolkit/MultipleViewPipeline,khusmann/MultipleViewPipeline,khusmann/MultipleViewPipeline,khusmann/MultipleViewPipeline,khusmann/MultipleViewPipeline,NeoGeographyToolkit/MultipleViewPipeline,NeoGeographyToolkit/MultipleViewPipeline,NeoGeographyToolkit/MultipleViewPipeline,NeoGeographyToolkit/MultipleViewPipeline,khusmann/MultipleViewPipeline