Replaced fwd slashes with backslashes for win to fix sass deps watch (#…

…1602)

src/Bundler.js

@@ -407,12 +407,11 @@ class Bundler extends EventEmitter {
   }
 
   async unwatch(path, asset) {
+    path = await fs.realpath(path);
     if (!this.watchedAssets.has(path)) {
       return;
     }
 
-    path = await fs.realpath(path);
-
     let watched = this.watchedAssets.get(path);
     watched.delete(asset);