Fix typo: __builtins__ should be __builtin__. (#2963)

third_party/2and3/boto/compat.pyi

@@ -10,7 +10,7 @@ expanduser: Any
 if sys.version_info >= (3, 0):
     StandardError = Exception
 else:
-    StandardError = __builtins__.StandardError
+    from __builtin__ import StandardError as StandardError
 
 long_type: Any
 unquote_str: Any

third_party/2and3/markupsafe/_compat.pyi

@@ -13,7 +13,7 @@ if sys.version_info[0] >= 3:
     unichr = chr
     int_types = int,
 else:
+    from __builtin__ import unichr as unichr
     text_type = unicode
     string_types = (str, unicode)
-    unichr = __builtins__.unichr
     int_types = (int, long)