Fix session variable comment (#3331)

Author: nateprewitt

botocore/configprovider.py

@@ -51,7 +51,7 @@
 #: NOTE: Fixing the spelling of this variable would be a breaking change.
 #: Please leave as is.
 BOTOCORE_DEFAUT_SESSION_VARIABLES = {
-    # logical:  config_file, env_var,        default_value, conversion_func
+    # logical:  config_file, env_var, default_value, conversion_func
     'profile': (None, ['AWS_DEFAULT_PROFILE', 'AWS_PROFILE'], None, None),
     'region': ('region', 'AWS_DEFAULT_REGION', None, None),
     'data_path': ('data_path', 'AWS_DATA_PATH', None, None),