In SketchController.nameCode, only switch tabs when adding file

When renaming a file, the current tab is already the correct
one, so no need to switch. This allows looking up the tab index based on
the SketchCode object, instead of doing a filename lookup.

app/src/processing/app/SketchController.java

@@ -368,11 +368,9 @@ public class SketchController {
         return;
       }
       sketch.addCode(code);
+      editor.selectTab(editor.findTabIndex(code));
     }
 
-    // set the new guy as current
-    editor.selectTab(editor.findTabIndex(newName));
-
     // update the tabs
     editor.header.rebuild();
   }