cveRecordSearchModule: remove unused "contentMessage"

Author: rlxdev

src/components/cveRecordSearchModule.vue

@@ -161,7 +161,6 @@ function startSearch() {
 
 function validateQueryString() {
 
-  const contentMessage = 'Enter words of alphanumeric characters OR a single CVE ID (CVE-YYYY-NNNN).';
   const isSearch = searchTypeBoolean.value;
   const searchValue = isSearch ? queryString.value : cveId;