Fix NeoOnnx 7d input

[zimka]

Off-by-one error.
BD_Count is equal to 7, so currently NeoOnnx checks that input tensor shape has strictly less than 7 dims.
However NeoML support 7d blobs, so this check should be adjusted.

BlobDesc.h
...
enum TBlobDim {
	BD_BatchLength = 0, // the sequence length
	BD_BatchWidth, // 1
	BD_ListSize, // 2
	BD_Height, //3
	BD_Width, //4
	BD_Depth, //5
	BD_Channels, //6

	BD_Count //7
};