Margin/Padding Added with Plugin

When I activate the plugin, it adds an additional 20pixels between image rows. I’d like to remove this, and have dug into the CSS files unsuccessfully.

Any idea how to remove the 20 pixels so that the margin between images reverts back to my original 10 pixels? I imagine it’s a simple fix, I just can’t locate the proper code.

Thanks much!

website is:
http://www.graceinlove.com

http://ww.wp.xz.cn/plugins/pinterest-pin-it-button-for-images/