Fix the z-index to keep thead behind dropdown #1457

Signed-off-by: tdruez <tdruez@nexb.com>

Author: tdruez

scanpipe/templates/scanpipe/base.html

@@ -39,7 +39,7 @@
       .is-grey-link {color: #7a7a7a;}
       .is-black-link:hover, .is-grey-link:hover {color: #3273dc; text-decoration: underline;}
       .navbar button.navbar-item {font-size: 1em;}
-      thead.is-sticky {position: sticky; top: -1px; z-index: 100; background-color: #fff;}
+      thead.is-sticky {position: sticky; top: -1px; z-index: 19; background-color: #fff;}
       #inputs-panel .panel-block.dropdown:hover {background-color: #f5f5f5;}
       #inputs-panel .dropdown-menu {width: 85%;}
       a.panel-block {word-break: break-all;}