add rocksdb secondary; fix read_only mode.

Signed-off-by: Jason Volk <jason@zemos.net>

src/service/globals/mod.rs

@@ -329,4 +329,7 @@ impl Service {
 
 	#[inline]
 	pub fn server_is_ours(&self, server_name: &ServerName) -> bool { server_name == self.config.server_name }
+
+	#[inline]
+	pub fn is_read_only(&self) -> bool { self.db.db.is_read_only() }
 }