Improve socket.bind error message

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-10-29.10:42:52.154>
labels = ['3.8', 'expert-IO']
title = 'Improve socket.bind error message'
updated_at = <Date 2020-10-29.10:43:40.098>
user = 'https://github.com/flying-sheep'

bugs.python.org fields:

activity = <Date 2020-10-29.10:43:40.098>
actor = 'flying sheep'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['IO']
creation = <Date 2020-10-29.10:42:52.154>
creator = 'flying sheep'
dependencies = []
files = []
hgrepos = []
issue_num = 42193
keywords = []
message_count = 1.0
messages = ['379865']
nosy_count = 1.0
nosy_names = ['flying sheep']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue42193'
versions = ['Python 3.8']