silence GCC warning on memmove

src/http_parser.cpp

@@ -617,7 +617,14 @@ restart_response:
 			span<char> chunk = buffer.subspan(
 				aux::numeric_cast<std::ptrdiff_t>(chunk_start - offset)
 				, aux::numeric_cast<std::ptrdiff_t>(chunk_end - chunk_start));
+#if defined __GNUC__ && __GNUC__ >= 7
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstringop-overflow"
+#endif
 			std::memmove(write_ptr, chunk.data(), std::size_t(chunk.size()));
+#if defined __GNUC__ && __GNUC__ >= 7
+#pragma GCC diagnostic pop
+#endif
 			write_ptr += chunk.size();
 		}
 		return buffer.first(write_ptr - buffer.data());