Improve comment in setup.py (scikit-learn#13661)

Author: kfrncs

sklearn/__init__.py

@@ -98,7 +98,7 @@ def setup_module(module):
     import numpy as np
     import random
 
-    # It could have been provided in the environment
+    # Check if a random seed exists in the environment, if not create one.
     _random_seed = os.environ.get('SKLEARN_SEED', None)
     if _random_seed is None:
         _random_seed = np.random.uniform() * (2 ** 31 - 1)