Removed unhelpful build script warning

gatsby/onCreateNode.js

@@ -45,13 +45,8 @@ module.exports = exports.onCreateNode = ({node, boundActionCreators, getNode}) =
       }
 
       if (!slug) {
+        // This will likely only happen for the partials in /content/home.
         slug = `/${relativePath.replace('.md', '.html')}`;
-
-        // This should only happen for the partials in /content/home,
-        // But let's log it in case it happens for other files also.
-        console.warn(
-          `Warning: No slug found for "${relativePath}". Falling back to default "${slug}".`,
-        );
       }
 
       // Used to generate URL to view this content.