Fix Panic when stopping Server before even started

[tretmar]

Fixing panics happening when the server get's the Stop() function called before it is even started.

By initialising the channel earlier, it can easily be closed.

[coveralls]

Pull Request Test Coverage Report for Build 8748620426

Details

• 6 of 6 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.006%) to 89.031%

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Totals
Change from base Build 8169798019:	0.006%
Covered Lines:	6526
Relevant Lines:	7330

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💛 - Coveralls

[tretmar]

Another option btw is to go for stuff like this:

if (channel != nil) {
    close(channel)
}

[hsteidl]

👍