Improve log after SECURITY-626 (#4443)

core/src/main/java/hudson/security/csrf/CrumbFilter.java

@@ -91,7 +91,7 @@ public class CrumbFilter implements Filter {
                 if (crumbIssuer.validateCrumb(httpRequest, crumbSalt, crumb)) {
                     valid = true;
                 } else {
-                    LOGGER.log(level, "Found invalid crumb {0}.  Will check remaining parameters for a valid one...", crumb);
+                    LOGGER.log(level, "Found invalid crumb {0}. If you are calling this URL with a script, please use the API Token instead. More information: https://jenkins.io/redirect/crumb-cannot-be-used-for-script", crumb);
                 }
             }