GL: extraneous newline.

Seems like nobody touched this file since 2018, when it was moved from
the base library to GL in 6d41597d1d.

src/Magnum/GL/BufferImage.cpp

@@ -138,7 +138,6 @@ template<UnsignedInt dimensions> void CompressedBufferImage<dimensions>::setData
     _dataSize = data.size();
 }
 
-
 template<UnsignedInt dimensions> void CompressedBufferImage<dimensions>::setData(const CompressedPixelStorage storage, const Magnum::CompressedPixelFormat format, const VectorTypeFor<dimensions, Int>& size, const Containers::ArrayView<const void> data, const BufferUsage usage) {
     setData(storage, compressedPixelFormat(format), size, data, usage);
 }