Enforce use of bool literals instead of integers

Using clang-tidy's `modernize-use-bool-literals`.
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-bool-literals.html

core/io/http_client.cpp

@@ -283,7 +283,7 @@ void HTTPClient::close() {
 	body_size = -1;
 	body_left = 0;
 	chunk_left = 0;
-	chunk_trailer_part = 0;
+	chunk_trailer_part = false;
 	read_until_eof = false;
 	response_num = 0;
 	handshaking = false;