Update __init__.py

Just fixing an issue with python 3.
Basically, you cannot do indentation mixing spaces and tabs in the same python file (https://www.python.org/dev/peps/pep-0008/#tabs-or-spaces)

bob/io/image/__init__.py

@@ -20,8 +20,8 @@ def get_config():
 # fix imghdr's jpeg detection to use the first two bytes (according to https://en.wikipedia.org/wiki/List_of_file_signatures)
 import imghdr
 def _test_jpeg(h, f):
-    if h.startswith('\xff\xd8'):
-        return "jpeg"
+  if h.startswith('\xff\xd8'):
+    return "jpeg"
 imghdr.tests.append(_test_jpeg)
 
 def load(filename, extension=None):
@@ -56,7 +56,7 @@ def load(filename, extension=None):
     if extension == 'auto':
       extension = imghdr.what(filename)
       if extension is None:
-	raise IOError("Could not detect the image type of file %s" % filename)
+        raise IOError("Could not detect the image type of file %s" % filename)
       extension = "." + extension
     f = bob.io.base.File(filename, 'r', extension)