BUILD: compression: include tools.h in compression.c

It needs it for memprintf() but it wasn't included.
diff --git a/src/compression.c b/src/compression.c
index 911d0ac..c9c0a30 100644
--- a/src/compression.c
+++ b/src/compression.c
@@ -34,6 +34,7 @@
 #include <haproxy/pool.h>
 #include <haproxy/stream.h>
 #include <haproxy/thread.h>
+#include <haproxy/tools.h>
 
 
 #if defined(USE_ZLIB)