OSSM-5001 Modified check for installed OpenSSL

Now checks for <openssl/types.h> instead of <openssl/ssl.h> because
<openssl/types.h> is only in OpenSSL 3.0.x. This ensures that if the host
only has OpenSSL 1.1.x headers, they will not be used.

Signed-off-by: Ted Poole <tpoole@redhat.com>

bssl-compat/cmake/openssl.cmake

@@ -1,7 +1,7 @@
 include(CheckIncludeFile)
 include(ExternalProject)
 
-check_include_file ("openssl/ssl.h" OS_OPENSSL_HEADERS)
+check_include_file ("openssl/types.h" OS_OPENSSL_HEADERS)
 find_library (OS_SSL_LIBRARY ssl)
 find_library (OS_CRYPTO_LIBRARY crypto)