curl: error out if wolfSSL is not usable

curl: error out if wolfSSL is not usable

When we explicitly declare, that we would like to have curl built with
wolfSSL support using `--with-wolfssl` configure option, then we should
make sure, that we either endup with curl having that support, or it
shouldn't be available at all, otherwise we risk, that we end up with
regressions like following:

  configure:25299: checking for wolfSSL_Init in -lwolfssl
  configure:25321: x86_64-openwrt-linux-musl-gcc -o conftest [snip]
  In file included from target-x86_64_musl/usr/include/wolfssl/wolfcrypt/dsa.h:33,
                   from target-x86_64_musl/usr/include/wolfssl/wolfcrypt/asn_public.h:35,
                  from target-x86_64_musl/usr/include/wolfssl/ssl.h:35,
                   from conftest.c:47:
  target-x86_64_musl/usr/include/wolfssl/wolfcrypt/integer.h:37:14: fatal error: wolfssl/wolfcrypt/sp_int.h: No such file or directory
       #include <wolfssl/wolfcrypt/sp_int.h>
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  compilation terminated.

and in the end thus produce curl without https support:

 curl: (1) Protocol "https" not supported or disabled in libcurl

So fix it, by making the working wolfSSL mandatory and error out in
configure step when that's not the case:

 checking for wolfSSL_Init in -lwolfssl... no
 configure: error: --with-wolfssl but wolfSSL was not found or doesn't work

References: #19005, #19547
Upstream-Status: Accepted [https://github.com/curl/curl/pull/9682]
Signed-off-by: Petr Štetiar <ynezz@true.cz>