Remove border radius because it has wrong background

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/generic/issue_box.scss

@@ -11,7 +11,6 @@
   color: #555;
   margin:20px 0;
   background: $box_bg;
-  border-top-left-radius: 5px;
   @include box-shadow(0 1px 1px rgba(0, 0, 0, 0.09));
 
   &.issue-box-closed {
@@ -112,7 +111,6 @@
     float: left;
     font-weight: bold;
     padding: 10px 15px;
-    border-top-left-radius: 5px;
   }
 
   .creator {