adding restricted height to active_users user icons, because pesky people like @cnvo have avatars that are higher than they are wide

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@@ -238,6 +238,7 @@
 		img {
 			border-radius: 50%;
 			width: 20px;
+			height: 20px;
 			margin-right: -12px;
 			vertical-align: middle;
 		}