[tex4ht] add package animate makes some math disappear from web page

[Michal Hoftich]

Hi Nasser,

it seems that animate package writes something into the dvi file,
which causes dvisvgm to terminate with fatal error. As it is declaring
it directly when the package is loaded, we can't disable it from a
.4ht file.

Easy fix is to include it conditionally only when compiling into PDF.
And probably reporting it to the package maintainers. Something like

 \ifdefined\HCode
    \endinput
  \fi

added at the beginning of the package should suffice.

Best regards,
Michal