PDFont.isSymbolic should fallback to false instead of true

[Hisham Said]

Hello,

I believe the following lines should fallback to false instead of true.

https://github.com/apache/pdfbox/blob/trunk/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/font/PDFont.java#L401-L402

{
    // unless we can prove that the font is symbolic, we assume that it is
not
    isSymbolic = true;
}

Thought to let you know.

Best Regards,
Hisham