BUG/MINOR: quic: fix type bug on "show quic" for 32-bits arch

Incorrect printf format specifier "%lu" was used on "show quic" handler
for uint64_t. This breaks build on 32-bits architecture. To fix this
portability issue, force an explicit cast to unsigned long long with
"%llu" specifier.

This must be backported up to 2.7.
diff --git a/src/quic_conn.c b/src/quic_conn.c
index c93484c..bf272c1 100644
--- a/src/quic_conn.c
+++ b/src/quic_conn.c
@@ -7788,8 +7788,10 @@
 			stream = eb64_entry(node, struct qc_stream_desc, by_id);
 			node = eb64_next(node);
 
-			chunk_appendf(&trash, "  | stream=%-8llu", (long long unsigned int)stream->by_id.key);
-			chunk_appendf(&trash, " off=%-8lu ack=%-8lu", stream->buf_offset, stream->ack_offset);
+			chunk_appendf(&trash, "  | stream=%-8llu", (unsigned long long)stream->by_id.key);
+			chunk_appendf(&trash, " off=%-8llu ack=%-8llu",
+			              (unsigned long long)stream->buf_offset,
+			              (unsigned long long)stream->ack_offset);
 
 			if (!(++i % 3)) {
 				chunk_appendf(&trash, "\n");