rename misleading sender_servername to origin

this is the X-Matrix origin/server, NOT the `"sender"``
user's server name.

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

src/api/ruma_wrapper/mod.rs

@@ -9,10 +9,12 @@ use crate::service::appservice::RegistrationInfo;
 
 /// Extractor for Ruma request structs
 pub(crate) struct Ruma<T> {
+	/// Request struct body
 	pub(crate) body: T,
 	pub(crate) sender_user: Option<OwnedUserId>,
 	pub(crate) sender_device: Option<OwnedDeviceId>,
-	pub(crate) sender_servername: Option<OwnedServerName>,
+	/// X-Matrix origin/server
+	pub(crate) origin: Option<OwnedServerName>,
 	pub(crate) json_body: Option<CanonicalJsonValue>, // This is None when body is not a valid string
 	pub(crate) appservice_info: Option<RegistrationInfo>,
 }