[libsoup] Fix a warning introduced in fix for bug 582002

[Dan Winship <danw src gnome org>]

commit 3907ea17b414bc2aa7ac6e29fd7000fff934f926
Author: Dan Winship <danw gnome org>
Date:   Fri May 15 10:26:34 2009 -0400

    Fix a warning introduced in fix for bug 582002
---
 libsoup/soup-message-io.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libsoup/soup-message-io.c b/libsoup/soup-message-io.c
index f4ecfb5..d3f0a1e 100644
--- a/libsoup/soup-message-io.c
+++ b/libsoup/soup-message-io.c
@@ -258,12 +258,12 @@ read_metadata (SoupMessage *msg, gboolean to_blank)
 			if (!to_blank)
 				break;
 			if (nread == 1 &&
-			    !strncmp (io->read_meta_buf->data +
+			    !strncmp ((char *)io->read_meta_buf->data +
 				      io->read_meta_buf->len - 2,
 				      "\n\n", 2))
 				break;
 			else if (nread == 2 &&
-				 !strncmp (io->read_meta_buf->data +
+				 !strncmp ((char *)io->read_meta_buf->data +
 					   io->read_meta_buf->len - 3,
 					   "\n\r\n", 3))
 				break;