COSMIT fix python2 -> python3 in comment

Author: lesteve

sklearn/svm/base.py

@@ -237,7 +237,7 @@ def _dense_fit(self, X, y, sample_weight, solver_type, kernel,
             if isinstance(kernel, six.types.UnicodeType):
                 kernel = str(kernel)
         if six.PY3:
-            # In python2 ensure kernel is utf8 unicode to prevent a TypeError
+            # In python3 ensure kernel is utf8 unicode to prevent a TypeError
             if isinstance(kernel, bytes):
                 kernel = str(kernel, 'utf8')