Cleanup core cmake config

 - Remove lz4 from link libraries, because it can be linked via
   EXTRA_CORE_LINK_LIBRARIES. It'd be more correct, because the
   open-source doesn't use lz4. Follow-up commit 55f968b4 ("msgpack:
   add stubs for compressed data support").

 - Add OpenSSL include directories unconditionally, because they are
   used in the open-source build since commit e5ec324d ("Move
   OpenSSL initialization to lib/core/ssl").

NO_DOC=cmake
NO_CHANGELOG=cmake

src/lib/core/CMakeLists.txt

@@ -49,11 +49,8 @@ else()
     list(APPEND core_sources ssl.c ssl_error.cc)
 endif()
 
-include_directories(${EXTRA_CORE_INCLUDE_DIRS})
-
-if(ENABLE_SSL)
-    include_directories(${OPENSSL_INCLUDE_DIR})
-endif()
+include_directories(${OPENSSL_INCLUDE_DIR}
+                    ${EXTRA_CORE_INCLUDE_DIRS})
 
 if (TARGET_OS_NETBSD)
     # A workaround for "undefined reference to `__gcc_personality_v0'"
@@ -76,7 +73,7 @@ if (ENABLE_BACKTRACE AND NOT TARGET_OS_DARWIN)
 endif()
 
 if (ENABLE_TUPLE_COMPRESSION)
-    target_link_libraries(core ${ZSTD_LIBRARIES} ${LZ4_LIBRARIES})
+    target_link_libraries(core ${ZSTD_LIBRARIES})
 endif()
 
 # Since fiber.top() introduction, fiber.cc, which is part of core