Fix format string injection when using option --write-info-json for video with percent sign in title. (Caused TypeError "not enough arguments for format string")

[mk-pmb]

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• Bug fix Option --write-info-json for video with percent sign in title causes TypeError "not enough arguments for format string" #32558
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Description of your pull request and other information

My change concatenates the filename verbatim to the output, instead of to the template that is fed into msg(). This way, percent signs in the filename will not trip up msg().

[dirkf]

Thanks!