[paperbox] Don't const_cast doc_keys to char** as const char** is expected by libtracker.

[Marko Anastasov <markoa src gnome org>]

commit 58f2ab6c33e6ad152bae14765c25f08e84c1b4d8
Author: Marko Anastasov <marko renderedtext com>
Date:   Wed May 27 18:55:03 2009 +0200

    Don't const_cast doc_keys to char** as const char** is expected by libtracker.
    
    Fixes bug #581740: Error while installing paperbox
---
 src/tracker-phone.cc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/tracker-phone.cc b/src/tracker-phone.cc
index b13c6de..3487c6f 100644
--- a/src/tracker-phone.cc
+++ b/src/tracker-phone.cc
@@ -334,7 +334,7 @@ namespace paperbox {
         results = tracker_metadata_get(tracker_connection_,
                                        SERVICE_DOCUMENTS,
                                        uri.c_str(),
-                                       const_cast<char**>(doc_keys),
+                                       doc_keys,
                                        &error);
 
         if (error) {