Fix unknown command keyword message

Author: Veirisa

driver/src/main/java/jdbc/client/helpers/query/parser/QueryParser.java

@@ -80,7 +80,7 @@ private QueryParser() {
             throw new SQLException(String.format(
                     "Query contains an unknown keyword for the command %s: %s.",
                     command,
-                    commandKeyword
+                    commandKeywordStr
             ));
         return commandKeyword;
     }