Bug 1507980: The z-index of select2 is too high

We need to have the z-index of the select2 search container
to be lower than the navigation menu z-index

behatnotneeded: design issue

Change-Id: I8daa8a67e0c7fa011728a23f3c25e68fd4a3b7f9
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>

htdocs/theme/raw/sass/select2.scss

@@ -162,7 +162,7 @@ html[dir="rtl"] .select2-container .select2-choice > .select2-chosen {
   height: auto;
   width: auto;
   opacity: 0;
-  z-index: 9998;
+  z-index: 997;
   /* styles required for IE to work */
   background-color: #fff;
   filter: alpha(opacity = 0);
@@ -172,7 +172,7 @@ html[dir="rtl"] .select2-container .select2-choice > .select2-chosen {
   width: 100%;
   margin-top: -1px;
   position: absolute;
-  z-index: 9999;
+  z-index: 998;
   top: 100%;
   background: #fff;
   color: #000;
@@ -253,7 +253,7 @@ html[dir="rtl"] .select2-container .select2-choice .select2-arrow b {
   padding-left: 4px;
   padding-right: 4px;
   position: relative;
-  z-index: 10000;
+  z-index: 999;
   white-space: nowrap;
   input {
     width: 100%;