perl-www-curl: add patch to ensure compatibility with curl 7.88

Patch comes from
https://github.com/openwrt/packages/pull/20540#issuecomment-1439537287



Fixes:
/home/username/works/openwrt/staging_dir/target-x86_64_glibc_custom/usr/include/curl/curl.h:2515:3: note: declared here
 2515 |   CURLFORM_CONTENTTYPE     CURL_DEPRECATED(7.56.0, "Use curl_mime_type()"),
      |   ^~~~~~~~~~~~~~~~~~~~
make[3]: *** [Makefile:347: Curl.o] Error 1

Signed-off-by: Stan Grishin <stangri@melmac.ca>