edited stylesheet with mr modal fixes and added to changelog

CHANGELOG.md

@@ -28,6 +28,7 @@ Please view this file on the master branch, on stable branches it's out of date.
   - Show full status link on MR & commit pipelines
   - Fix documents and comments on Build API `scope`
   - Refactor email, use setter method instead AR callbacks for email attribute (Semyon Pupkov)
+  - Shortened merge request modal to let clipboard button not overlap
 ## 8.13.2
   - Fix builds dropdown overlapping bug !7124

app/assets/stylesheets/pages/merge_requests.scss

@@ -279,6 +279,10 @@
 #modal_merge_info .modal-dialog {
   width: 600px;
+  .dark {
+    margin-right: 40px;
+  }
+
   .btn-clipboard {
     @extend .pull-right;