cmake: respect GNUTLS_LIBRARY_DIRS in libcurl.pc and curl-config

Authored-by: Kai Pastor
Ref: microsoft/vcpkg@0ed3bfe
Closes curl#16190

CMakeLists.txt

@@ -851,7 +851,7 @@ if(CURL_USE_GNUTLS)
   set(_ssl_enabled ON)
   set(USE_GNUTLS ON)
   list(APPEND CURL_LIBS ${GNUTLS_LIBRARIES} ${NETTLE_LIBRARIES})
-  list(APPEND CURL_LIBDIRS ${NETTLE_LIBRARY_DIRS})
+  list(APPEND CURL_LIBDIRS ${GNUTLS_LIBRARY_DIRS} ${NETTLE_LIBRARY_DIRS})
   list(APPEND LIBCURL_PC_REQUIRES_PRIVATE "gnutls" ${NETTLE_PC_REQUIRES})
   include_directories(SYSTEM ${GNUTLS_INCLUDE_DIRS} ${NETTLE_INCLUDE_DIRS})
   link_directories(${NETTLE_LIBRARY_DIRS})