Fixed #134 - Error with calendar year navigator

src/components/calendar/Calendar.vue

@@ -2071,6 +2071,7 @@ export default {
             return this.dateFormat || this.locale.dateFormat;
         },
         yearOptions() {
+            if (this.yearRange) {
                 let $vm = this;
                 const years = this.yearRange.split(':');
                 let yearStart = parseInt(years[0]);
@@ -2089,6 +2090,10 @@ export default {
                 }
 
                 return yearOptions;
+            }
+            else {
+                return null;
+            }
         },
         monthPickerValues() {
             let monthPickerValues = [];