* Fix invite_url_re
Found that the regex used previously could falsely catch strings such as discord member and discord gggggg which aren't invites and shouldn't be caught, testing with this regex string still catches all invite url variations while allowing these other previously caught strings to keep working
* Update redbot/core/utils/common_filters.py
Co-Authored-By: jack1142 <6032823+jack1142@users.noreply.github.com>
Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>