Revert ctx state for remote backend when user clicks on previous

gui/src/installer/mod.rs

@@ -72,6 +72,10 @@ impl Installer {
         {
             self.current -= 1;
         }
+
+        if let Some(step) = self.steps.get(self.current) {
+            step.revert(&mut self.context)
+        }
     }
 
     pub fn new(

gui/src/installer/step/backend.rs

@@ -260,6 +260,12 @@ impl Step for ChooseBackend {
         true
     }
 
+    /// If user clicks on previous to get back to the select backend, we revert the applied remote
+    /// backend on the context.
+    fn revert(&self, ctx: &mut Context) {
+        ctx.remote_backend = None;
+    }
+
     fn view<'a>(
         &'a self,
         _hws: &'a HardwareWallets,

gui/src/installer/step/mod.rs

@@ -50,6 +50,7 @@ pub trait Step {
     fn apply(&mut self, _ctx: &mut Context) -> bool {
         true
     }
+    fn revert(&self, _ctx: &mut Context) {}
     fn stop(&self) {}
 }