set history limit

- history limit is now stored by the client. this patch ensure
only to keep the data. It does not clean the history yet.

Change-Id: Ia95b4589f9ec71f5c84fefa0341080346ef874ab
diff --git a/data/cx.ring.RingGnome.gschema.xml b/data/cx.ring.RingGnome.gschema.xml
index 09b1897..8534739 100644
--- a/data/cx.ring.RingGnome.gschema.xml
+++ b/data/cx.ring.RingGnome.gschema.xml
@@ -58,5 +58,10 @@
         <summary>The user selected account.</summary>
         <description>The account id of the user selected account; if empty there is no valid account selected.</description>
     </key>
+    <key name="history-limit" type="i">
+        <default>0</default>
+        <summary>Number of days to store the history.</summary>
+        <description>Keep history only within the limit. 0 for unlimited history.</description>
+    </key>
   </schema>
 </schemalist>