Remove extra lines on downstream

Fix the extra lines that happen on
the downstream column. UX wants them
removed but I found another use case
we need to fix.

app/assets/javascripts/pipelines/components/graph/linked_pipeline.vue

@@ -42,7 +42,6 @@ export default {
 
 <template>
   <li class="linked-pipeline build">
-    <div class="curve"></div>
     <gl-button
       :id="buttonId"
       v-gl-tooltip

ee/app/assets/stylesheets/pages/pipelines.scss

@@ -132,6 +132,10 @@
   .linked-pipeline.build {
     height: 41px;
 
+    &::before {
+      content: none;
+    }
+
     // apply custom dimensions to connector before and after for triangle arrow
     &.flat-connector-before {
       @include flat-connector-before($linked-project-column-margin);