compatibility with 5.5

git-svn-id: https://plugins.svn.wordpress.org/gra4-social-network/trunk@801860 b8457f37-d9ea-0310-8a92-e5e31aec5664
screenshot change

git-svn-id: https://plugins.svn.wordpress.org/gra4-social-network/trunk@804370 b8457f37-d9ea-0310-8a92-e5e31aec5664
demo website url changed

git-svn-id: https://plugins.svn.wordpress.org/gra4-social-network/trunk@804431 b8457f37-d9ea-0310-8a92-e5e31aec5664