[pvr.tvh] wait for 30 seconds when deleting recordings

Chances are pretty high that the response will otherwise timeout and an 
error dialog will be triggered. This is because deleting recordings can take 
quite a while (ideally it should be fixed in tvheadend).

addons/pvr.tvh/src/Tvheadend.cpp

@@ -206,8 +206,8 @@ PVR_ERROR CTvheadend::SendDvrDelete ( uint32_t id, const char *method )
   htsmsg_t *m = htsmsg_create_map();
   htsmsg_add_u32(m, "id", id);
 
-  /* Send and Wait */
-  if ((m = m_conn.SendAndWait(method, m)) == NULL)
+  /* Send and wait a bit longer than usual */
+  if ((m = m_conn.SendAndWait(method, m, 30)) == NULL)
   {
     tvherror("failed to cancel/delete DVR entry");
     return PVR_ERROR_SERVER_ERROR;