[evince] libdocument: Fix const warning

[Christian Persch <chpe src gnome org>]

commit 1011dfd20ece7c373e1757766338bd7bf090b50d
Author: Christian Persch <chpe gnome org>
Date:   Fri Jul 26 21:41:59 2013 +0200

    libdocument: Fix const warning

 libdocument/ev-file-helpers.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libdocument/ev-file-helpers.c b/libdocument/ev-file-helpers.c
index 902ed40..6691a55 100644
--- a/libdocument/ev-file-helpers.c
+++ b/libdocument/ev-file-helpers.c
@@ -629,7 +629,7 @@ compression_run (const gchar       *uri,
        }
 
        argv[0] = cmd;
-       argv[1] = compress ? "-c" : "-cd";
+       argv[1] = compress ? (char *) "-c" : (char *) "-cd";
        argv[2] = filename;
        argv[3] = NULL;