Don't use project path as fallback icon for item with no path

Stops the project folder icon appearing in places that don't make sense
like settings and new files.

Test Plan:

  * Opened settings and didn't see the project folder icon
  * Closed all tabs and saw the project folder icon

src/workspace-view.coffee

@@ -217,7 +217,7 @@ class WorkspaceView extends View
     if projectPath = atom.project.getPath()
       if item = @getModel().getActivePaneItem()
         title = "#{item.getTitle?() ? 'untitled'} - #{projectPath}"
-        proxyIconPath = item.getPath?() ? projectPath
+        proxyIconPath = item.getPath?() ? ''
         @setTitle(title, proxyIconPath)
       else
         @setTitle(projectPath, projectPath)