tweak style

I thought I wanted to add something for the no domain case
(e.g., a document with file://) but I don't

.gitignore

@@ -1,2 +1,3 @@
 rosenrot
 # don't save the binary file, as it doesn't play nicely with https://difftastic.wilfred.me.uk
+webkit/

plugins/style/style.js

@@ -183,6 +183,8 @@ switch (document.domain) {
       }
     `;
 		break;
+	case "":
+		break;
 	default:
 		console.log(`Domain: ${document.domain}`);
 		console.log("No custom style");