Minor UI fixes (#27022)

* MM-58170 - Updating remove license modal

* MM-58211 - Updating color on sign up page url

* updating css

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Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/platform/components/src/generic_modal/generic_modal.scss

@@ -18,6 +18,10 @@
         }
     }
 
+    .no-header__img {
+        margin-top: -40px;
+    }
+
     .modal-body {
         max-height: 100%;
         padding: 0;