restore transpose of jpeg x,y

x, y were reversed in earlier commit

IPython/core/display.py

@@ -951,7 +951,8 b' def _jpegxy(data):'
             # read another block
             idx += 2
 
-    return struct.unpack('>HH', data[iSOF+5:iSOF+9])
+    h, w = struct.unpack('>HH', data[iSOF+5:iSOF+9])
+    return w, h
 
 def _gifxy(data):
     """read the (width, height) from a GIF header"""