Fix typo in README. Fixed googleworkspace#3.

Author: Eric Koleda

README.md

@@ -80,7 +80,7 @@ service for the Google Drive API.
 
           // Sets the login hint, which will prevent the account chooser screen 
           // from being shown to users logged in with multiple accounts.
-          .setParam('login_hint', Session.getActiveUser.getEmail())
+          .setParam('login_hint', Session.getActiveUser().getEmail())
 
           // Requests offline access.
           .setParam('access_type', 'offline')