Bug 31973: Restore background color to message-style alerts

This patch restores the background color to message-style alerts, those
which use the markup <div class="dialog message">. These alerts should
stand out more to the user.

To test, apply the patch and rebuild the staff interface CSS.

- Test areas which use the message-style dialog. Perhaps the easiest
  example is to try to view a bibliographic record which doesn't exist:

  /cgi-bin/koha/catalogue/detail.pl?biblionumber=1234567890

- It can also be found as a confirmation when deleting a basket in
  Acquisitions, deleting a patron attribute type in Administration,
  updating a Z39.50 server in Administration, etc.

- Confirm that the alert looks correct and is suitable visible.

Signed-off-by: David Nind <david@davidnind.com>

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>

koha-tmpl/intranet-tmpl/prog/css/src/staff-global.scss

@@ -1622,7 +1622,6 @@ i {
 }
 
 .dialog {
-    border-radius: 2px;
     margin: 1em auto;
     padding: .5em;
     text-align: center;
@@ -1747,7 +1746,7 @@ i {
     }
 
     &.message {
-        background-color: #ffffff;
+        background-color: #CFE2FF;
         text-align: center;
 
         ul,
@@ -1763,7 +1762,7 @@ i {
 
     &.alert,
     &.error {
-        background-color: rgb(255, 237, 135);
+        background-color: rgb( 255, 237, 135 );
         color: inherit;
         text-align: center;
         text-shadow: none;