Missing default value for tag `msg-param-sender-count`

[Larandar]

Since a few days I get the following error from time to time from twitch:

2024-09-29T09:00:17.760002Z ERROR client_loop:connection:main_loop: twitch_irc::connection::event_loop: Failed to parse incoming message as ServerMessage (emitting as generic instead): Could not parse IRC message @subscriber=1;user-type=;msg-param-sub-plan=1000;login=twitch;badge-info=subscriber/2;msg-param-mass-gift-count=1;room-id=241636;system-msg=We\sadded\s1\sGift\sSubs\sto\sMobbatFol's\sgift!;user-id=12826;badges=subscriber/2,gold-pixel-heart/1;flags=;tmi-sent-ts=1727600417671;msg-param-origin-id=3967552525803674582;msg-id=submysterygift;msg-param-gift-match-bonus-count=1;msg-param-gift-match-extra-count=0;msg-param-community-gift-id=3967552525803674582;emotes=;color=#8A2BE2;msg-param-gift-match-gifter-display-name=MobbatFol;vip=0;mod=0;id=5b9a3135-10f4-4c77-96b9-f6d9edf66731;display-name=Twitch;msg-param-gift-match=bonus :tmi.twitch.tv USERNOTICE #dunkorslam as ServerMessage: No tag present under key `msg-param-sender-count` id=0

[Larandar]

After investigation and testing, it seems that it happens only when Twitch gift sub during SUBtember; I proposed a PR that handles it as a pure edge case

[RAnders00]

Thank you for the bug report!