fix: /watching channel jumping around

[Nerixyz]

Pull request checklist:

• CHANGELOG.md was updated, if applicable

Description

When the extension sends multiple messages with the same channel, Chatterino will always set the channel and thus dispatch a channel-changed signal (which causes a re-layout) even if the channel was already set.

Maybe this could be done in IndirectChannel::reset instead?

chatterino2/src/common/Channel.cpp

Lines 453 to 459 in 3924861

	void IndirectChannel::reset(ChannelPtr channel)
	{
	assert(this->data_->type != Channel::Type::Direct);
	this->data_->channel = std::move(channel);
	this->data_->changed.invoke();
	}

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"