Tiny tweak in forms css.

static/sora/css/sora.css

@@ -837,7 +837,7 @@ form fieldset{border-top:1px solid #e8e8e8;margin:0px;padding:0px;padding-top:16
 form fieldset .control-group{padding-bottom:4px;}
 form fieldset .control-group:last-child{padding-bottom:0px;}
 form fieldset.first{border-top:none;padding-top:0px;}
-form fieldset.last{padding-bottom:0px;margin-bottom:-8px;}
+form fieldset.last{padding-bottom:0px;margin-bottom:8px;}
 .form-actions{margin-top:0px;}
 textarea{resize:vertical;}
 .radio-group,.select-multiple,.yes-no-switch{margin-bottom:8px;}.radio-group label,.select-multiple label,.yes-no-switch label{color:#000000;font-weight:normal;}

static/sora/css/sora/forms.less

@@ -37,7 +37,7 @@ form {
   
   fieldset.last {
     padding-bottom: 0px;
-    margin-bottom: -8px;
+    margin-bottom: 8px;
   }
 }