Fix handling of IRC color control sequences

An extra comma was being added after the control sequences
An empty color control sequence was not handled. It is supposed to
remove all color schemes.
14 jobs for eugeneso/irc_color_fix in 9 minutes and 51 seconds (queued for 9 seconds)
Status Job ID Name Coverage
  Build
passed #32658
FreeBSD
jsdoor-freebsd

00:07:27

passed #32659
Linux
jsdoor-linux

00:06:20

passed #32661
FreeBSD
jsdoor-windows

00:01:55

passed #32653
FreeBSD
sbbs-freebsd

00:09:00

passed #32648
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sbbs-linux

00:09:46

passed #32651
Windows
sbbs-windows

00:06:00

passed #32660
FreeBSD
sexpots-freebsd

00:03:21

passed #32649
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sexpots-linux

00:00:39

passed #32652
Windows
sexpots-windows

00:00:55

passed #32656
FreeBSD
syncdraw-freebsd

00:03:43

passed #32657
Linux
syncdraw-linux

00:01:22

passed #32654
FreeBSD
syncterm-freebsd

00:04:30

passed #32650
Linux
syncterm-linux

00:03:14

passed #32655
FreeBSD
syncterm-windows

00:05:03