use single global function for server name local and user local checking

Signed-off-by: strawberry <strawberry@puppygock.gay>

src/utils/server_name.rs

@@ -0,0 +1,8 @@
+//! utilities for doing/checking things with ServerName's/server_name's
+
+use ruma::ServerName;
+
+use crate::services;
+
+/// checks if `server_name` is ours
+pub(crate) fn server_is_ours(server_name: &ServerName) -> bool { server_name == services().globals.config.server_name }