Don't switch to nightly when edition 2021 is enabled

Closes #750

Author: shepmaster

ui/frontend/actions.ts

@@ -165,16 +165,9 @@ export const changeChannel = (channel: Channel) =>
 export const changeMode = (mode: Mode) =>
   createAction(ActionType.ChangeMode, { mode });
 
-const changeEditionRaw = (edition: Edition) =>
+export const changeEdition = (edition: Edition) =>
   createAction(ActionType.ChangeEdition, { edition });
 
-export const changeEdition = (edition: Edition): ThunkAction => dispatch => {
-  if (edition == Edition.Rust2021) {
-    dispatch(changeChannel(Channel.Nightly));
-  }
-  dispatch(changeEditionRaw(edition));
-}
-
 export const changeBacktrace = (backtrace: Backtrace) =>
   createAction(ActionType.ChangeBacktrace, { backtrace });
 
@@ -814,7 +807,7 @@ export type Action =
   | ReturnType<typeof changeBacktrace>
   | ReturnType<typeof changeChannel>
   | ReturnType<typeof changeDemangleAssembly>
-  | ReturnType<typeof changeEditionRaw>
+  | ReturnType<typeof changeEdition>
   | ReturnType<typeof changeEditor>
   | ReturnType<typeof changeFocus>
   | ReturnType<typeof changeKeybinding>