show gxs message store period in gui, set forums store period to one year

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@8206 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/retroshare/rsgxsifacehelper.h

@@ -208,6 +208,14 @@ public:
 		return mGxs->setGroupReputationCutOff(token, grpId, CutOff);
 	}
 
+    /*!
+     * @return storage time of messages in months
+     */
+    int getStoragePeriod()
+    {
+        return mGxs->getStoragePeriod();
+    }
+
 private:
 
     RsGxsIface* mGxs;