Update contrib/util/check-config.sh

Co-authored-by: Brad Davidson <brad@oatmail.org>
Signed-off-by: Rishikesh Nair <42700059+rishinair11@users.noreply.github.com>
(cherry picked from commit 82cfacb)
Signed-off-by: Brad Davidson <brad.davidson@rancher.com>

contrib/util/check-config.sh

@@ -55,7 +55,7 @@ is_set_as_module() {
 }
 
 color() {
-  if [[ -n "$NO_COLOR" ]]; then
+  if [ -n "$NO_COLOR" ]; then
     return
   fi