Fix event listener removal

Was terribly broken.
14 jobs for master in 9 minutes and 28 seconds (queued for 12 seconds)
Status Name Job ID Coverage
  Build
passed jsdoor-freebsd #18418
FreeBSD

00:05:33

passed jsdoor-linux #18419
Linux

00:06:03

passed jsdoor-windows #18421
FreeBSD

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passed sbbs-freebsd #18413
FreeBSD

00:07:31

passed sbbs-linux #18408
Linux

00:08:30

passed sbbs-windows #18411
Windows

00:05:06

passed sexpots-freebsd #18420
FreeBSD

00:00:16

passed sexpots-linux #18409
Linux

00:00:20

passed sexpots-windows #18412
Windows

00:00:25

passed syncdraw-freebsd #18416
FreeBSD

00:00:35

passed syncdraw-linux #18417
Linux

00:00:55

passed syncterm-freebsd #18414
FreeBSD

00:01:26

passed syncterm-linux #18410
Linux

00:02:19

passed syncterm-windows #18415
FreeBSD

00:02:31