Fix palette type. (#27)

mmseg/models/segmentors/base.py

@@ -242,8 +242,7 @@ class BaseSegmentor(nn.Module):
                     0, 255, size=(len(self.CLASSES), 3))
             else:
                 palette = self.PALETTE
-        else:
-            palette = np.array(palette)
+        palette = np.array(palette)
         assert palette.shape[0] == len(self.CLASSES)
         assert palette.shape[1] == 3
         assert len(palette.shape) == 2