gh-2827 Configmgr - Provide msg when validation finds no issue

  - A pop message will indicate when validation completes with no issues

Signed-off-by: Gleb Aronsky <gleb.aronsky@lexisnexis.com>

esp/files/scripts/configmgr/navtree.js

@@ -2006,6 +2006,8 @@ function validateEnvironment() {
           var temp1 = temp[1].split(/<\/td>/g);
           promptValidationErrs(temp1[0]);
         }
+        else
+          alert("No issues detected.");
       }
       else {
         getWaitDlg().hide();