email.utils.parsedate and email.utils.parsedate_tz corrected to be passable to time.mktime (#497)

Also email.utils.parsedate_tz 10th element can be None if no timezone is specified

Author: peterdotran

stdlib/3/email/utils.pyi

@@ -5,15 +5,15 @@ from email.charset import Charset
 import datetime
 
 _ParamType = Union[str, Tuple[Optional[str], Optional[str], str]]
-_PDTZ = Tuple[str, str, str, str, str, str, str, str, str, str]
+_PDTZ = Tuple[int, int, int, int, int, int, int, int, int, Optional[int]]
 
 def quote(str: str) -> str: ...
 def unquote(str: str) -> str: ...
 def parseaddr(address: str) -> Tuple[str, str]: ...
 def formataddr(pair: Tuple[str, str],
                charset: Union[str, Charset] = ...) -> str: ...
 def getaddresses(fieldvalues: List[str]) -> List[Tuple[str, str]]: ...
-def parsedate(date: str) -> Optional[Tuple[str, str, str, str, str, str, str, str, str]]: ...
+def parsedate(date: str) -> Optional[Tuple[int, int, int, int, int, int, int, int, int]]: ...
 def parsedate_tz(date: str) -> Optional[_PDTZ]: ...
 def parsedate_to_datetime(date: str) -> datetime.datetime: ...
 def mktime_tz(tuple: _PDTZ) -> int: ...