Improve error message in SpatialConvolutionMM
Improve error message in SpatialConvolutionMM

Better error message when number of input channels does not match the expected value

sagarwaghmare69/nn,PraveerSINGH/nn,diz-vara/nn,eriche2016/nn,nicholas-leonard/nn,andreaskoepf/nn,jonathantompson/nn,elbamos/nn,kmul00/nn,caldweln/nn,xianjiec/nn,joeyhng/nn,apaszke/nn,jhjin/nn,colesbury/nn