REORG: include: move common/chunk.h to haproxy/chunk.h

No change was necessary, it was already properly split.
diff --git a/src/fcgi-app.c b/src/fcgi-app.c
index 5b11680..f088900 100644
--- a/src/fcgi-app.c
+++ b/src/fcgi-app.c
@@ -11,7 +11,7 @@
  */
 
 #include <haproxy/api.h>
-#include <common/chunk.h>
+#include <haproxy/chunk.h>
 #include <common/cfgparse.h>
 #include <haproxy/errors.h>
 #include <common/standard.h>