[BUGFIX] Add check to make sure num_group is non-zero (#20186)
[BUGFIX] Add check to make sure num_group is non-zero (#20186)

* add check for group not equal zero

* num_group in convolution must be positive
szha/mxnet,tlby/mxnet,szha/mxnet,szha/mxnet,DickJC123/mxnet,szha/mxnet,tlby/mxnet,tlby/mxnet,apache/incubator-mxnet,tlby/mxnet,szha/mxnet,apache/incubator-mxnet,tlby/mxnet,tlby/mxnet,tlby/mxnet,DickJC123/mxnet,szha/mxnet,DickJC123/mxnet,tlby/mxnet,szha/mxnet,apache/incubator-mxnet,DickJC123/mxnet,szha/mxnet,tlby/mxnet,szha/mxnet,apache/incubator-mxnet,tlby/mxnet