[gcab] trivial: Clarify the GCabCompression introspection

[Richard Hughes <rhughes src gnome org>]

commit 09968232a90f2c302f612355a7058630abefd793
Author: Richard Hughes <richard hughsie com>
Date:   Tue Dec 12 21:04:59 2017 +0000

    trivial: Clarify the GCabCompression introspection

 libgcab/gcab-folder.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/libgcab/gcab-folder.h b/libgcab/gcab-folder.h
index 9b1d65c..d68a10f 100644
--- a/libgcab/gcab-folder.h
+++ b/libgcab/gcab-folder.h
@@ -47,8 +47,8 @@ typedef struct _GCabFolder GCabFolder;
  * GCabCompression:
  * @GCAB_COMPRESSION_NONE: No compression.
  * @GCAB_COMPRESSION_MSZIP: MSZIP compression.
- * @GCAB_COMPRESSION_QUANTUM: QUANTUM compression.
- * @GCAB_COMPRESSION_LZX: LZX compression.
+ * @GCAB_COMPRESSION_QUANTUM: QUANTUM compression (unsupported).
+ * @GCAB_COMPRESSION_LZX: LZX compression (only decompression supported).
  * @GCAB_COMPRESSION_MASK: compression value mask.
  *
  * Compression used by the #GCabFolder.