BZ#2021367: change 'than' to 'that'

Author: jldohmann

modules/nw-customize-ingress-error-pages.adoc

@@ -16,7 +16,7 @@ By default, the HAProxy router serves only a 503 error page when the application
 
 [NOTE]
 ====
-If you use the {product-title} default 503 error code page as a template for your customizations, the headers in the file require an editor than can use CRLF line endings.
+If you use the {product-title} default 503 error code page as a template for your customizations, the headers in the file require an editor that can use CRLF line endings.
 ====
 
 .Procedure