[Cin] making filegif optional

[Andrew Randrianasulu]

because Debian 8.11/ppc only have giflib4, and Cingg fails to use
it/compile with it.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cinelerra-gg.org/pipermail/cin/attachments/20220406/cca3cd1d/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Make-filegif-optional.patch
Type: text/x-diff
Size: 3370 bytes
Desc: not available
URL: <https://lists.cinelerra-gg.org/pipermail/cin/attachments/20220406/cca3cd1d/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0002-filegif-conditional-in-formatpopup.C.patch
Type: text/x-diff
Size: 761 bytes
Desc: not available
URL: <https://lists.cinelerra-gg.org/pipermail/cin/attachments/20220406/cca3cd1d/attachment-0001.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0003-Slightly-more-conditions-in-probe-order.patch
Type: text/x-diff
Size: 827 bytes
Desc: not available
URL: <https://lists.cinelerra-gg.org/pipermail/cin/attachments/20220406/cca3cd1d/attachment-0002.bin>