cmake, refactor: Move HAVE_EVHTTP_... to libevent interface

cmake/bitcoin-build-config.h.in

@@ -71,9 +71,6 @@
    */
 #cmakedefine01 HAVE_DECL_SETSID
 
-/* Define this symbol if evhttp_connection_get_peer expects const char** */
-#cmakedefine HAVE_EVHTTP_CONNECTION_GET_PEER_CONST_CHAR 1
-
 /* Define to 1 if fdatasync is available. */
 #cmakedefine HAVE_FDATASYNC 1
 

cmake/module/FindLibevent.cmake

@@ -35,7 +35,9 @@ function(check_evhttp_connection_get_peer target)
     " HAVE_EVHTTP_CONNECTION_GET_PEER_CONST_CHAR
   )
   cmake_pop_check_state()
-  set(HAVE_EVHTTP_CONNECTION_GET_PEER_CONST_CHAR ${HAVE_EVHTTP_CONNECTION_GET_PEER_CONST_CHAR} PARENT_SCOPE)
+  target_compile_definitions(${target} INTERFACE
+    $<$<BOOL:${HAVE_EVHTTP_CONNECTION_GET_PEER_CONST_CHAR}>:HAVE_EVHTTP_CONNECTION_GET_PEER_CONST_CHAR>
+  )
 endfunction()
 
 set(_libevent_components core extra)

src/httpserver.cpp

@@ -2,8 +2,6 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <bitcoin-build-config.h> // IWYU pragma: keep
-
 #include <httpserver.h>
 
 #include <chainparamsbase.h>