Fix mri_demo.py fails with mpl 1.2.0rc1

Author: cgohlke

examples/pylab_examples/mri_demo.py

@@ -4,7 +4,7 @@
 from pylab import *
 import matplotlib.cbook as cbook
 # data are 256x256 16 bit integers
-dfile = cbook.get_sample_data('s1045.ima')
+dfile = cbook.get_sample_data('s1045.ima.gz')
 im = np.fromstring(dfile.read(), np.uint16).astype(float)
 im.shape = 256, 256