Use javasript event only instead of href for avatars

One more think, I think this one need to be change as well:

in test/javascripts/widgets/post-test.js.es6

   assert.ok(this.$('.who-liked').length === 1);
	      assert.ok(this.$('.who-liked a.trigger-user-card').length === 1);

	      assert.ok(this.$('.who-liked').length === 0);
	      assert.ok(this.$('.who-liked a.trigger-user-card').length === 0);

to:

  assert.ok(this.$('.who-liked').length === 1);
    	      assert.ok(this.$('.who-liked span.trigger-user-card').length === 1);

    	      assert.ok(this.$('.who-liked').length === 0);
    	      assert.ok(this.$('.who-liked span.trigger-user-card').length === 0);