Remove last separator in CsvReportRenderer

[kanzungjak]

The CsvReportRenderer adds a separator after every entry, which isn't specified according to RFC4180 https://tools.ietf.org/html/rfc4180.

if (includeHeaderLine) {
    output <<  ${quote('artifact')}$separator${quote('moduleUrl')}$separator${quote('moduleLicense')}$separator${quote('moduleLicenseUrl')}$separator$nl"
}