Update crates/nu-plugin-engine/src/persistent.rs

Thanks Ian!

Co-authored-by: Ian Manske <ian.manske@pm.me>

crates/nu-plugin-engine/src/persistent.rs

@@ -312,7 +312,7 @@ impl RegisteredPlugin for PersistentPlugin {
             // RAII guard that will be stored on the plugin.
             let plugin = Arc::downgrade(&self);
             handlers.register(Box::new(move || {
-                // write a Ctrl-C packet through the PluginInterface is the plugin is alive and
+                // write a Ctrl-C packet through the PluginInterface if the plugin is alive and
                 // running
                 if let Some(plugin) = plugin.upgrade() {
                     if let Ok(mutable) = plugin.mutable.lock() {