own dataset: Shapes (64, 4, 4, 256) and (64, 3, 3, 256) are not compatible

Hi there,

When using my own dataset (28x28, grayscale), I get an error for this line in `model.py`:

`g_optim = tf.train.AdamOptimizer(config.learning_rate, beta1=config.beta1) \`
`.minimize(self.g_loss, var_list=self.g_vars)`

error:
`Traceback (most recent call last):
File "...tensorflow/python/framework/tensor_shape.py", line 575, in merge_with
new_dims.append(dim.merge_with(other[i]))`
`File "...tensorflow/python/framework/tensor_shape.py", line 133, in merge_with
self.assert_is_compatible_with(other)`
`File "...tensorflow/python/framework/tensor_shape.py", line 108, in assert_is_compatible_with
% (self, other))`
`ValueError: Dimensions 4 and 3 are not compatible`
`During handling of the above exception, another exception occurred:`
`Traceback (most recent call last):`
` File "main.py", line 74, in `
` tf.app.run()`
`File "...tensorflow/python/platform/app.py", line 30, in run`
` sys.exit(main(sys.argv[:1] + flags_passthrough))`
` File "main.py", line 59, in main`
` dcgan.train(FLAGS)`
`File "...DCGAN-tensorflow/model.py", line 139, in train`
`.minimize(self.g_loss, var_list=self.g_vars)`
` File "...tensorflow/python/training/optimizer.py", line 196, in minimize`
` grad_loss=grad_loss)`
`File "...tensorflow/python/training/optimizer.py", line 253, in compute_gradients`
`colocate_gradients_with_ops=colocate_gradients_with_ops)`
`File "...tensorflow/python/ops/gradients.py", line 491, in gradients`
`in_grad.set_shape(t_in.get_shape())`
`File "...tensorflow/python/framework/ops.py", line 408, in set_shape`
`self._shape = self._shape.merge_with(shape)`
`File "...tensorflow/python/framework/tensor_shape.py", line 579, in merge_with`
`(self, other))`
`ValueError: Shapes (64, 4, 4, 256) and (64, 3, 3, 256) are not compatible`

Any advice on how to fix this?