Before
# VGG block 3
self.conv2 = nn.Conv2d(16, 8, (3,3))
self.act3 = nn.ReLU()
self.pool3 = nn.MaxPool2d((2,2), stride=(2,2))

After
# VGG block 3
self.conv3 = nn.Conv2d(16, 8, (3,3))
self.act3 = nn.ReLU()
self.pool3 = nn.MaxPool2d((2,2), stride=(2,2))