fix: click event compatible with xhtml (#550)

Author: mengxiong10

src/calendar/table-date.vue

@@ -151,7 +151,7 @@ export default {
     },
     handleCellClick(evt) {
       let { target } = evt;
-      if (target.tagName === 'DIV') {
+      if (target.tagName.toUpperCase() === 'DIV') {
         target = target.parentNode;
       }
       const date = target.getAttribute('data-date');

src/calendar/table-month.vue

@@ -88,7 +88,7 @@ export default {
     },
     handleClick(evt) {
       let { target } = evt;
-      if (target.tagName === 'DIV') {
+      if (target.tagName.toUpperCase() === 'DIV') {
         target = target.parentNode;
       }
       const month = target.getAttribute('data-month');

src/calendar/table-year.vue

@@ -91,7 +91,7 @@ export default {
     },
     handleClick(evt) {
       let { target } = evt;
-      if (target.tagName === 'DIV') {
+      if (target.tagName.toUpperCase() === 'DIV') {
         target = target.parentNode;
       }
       const year = target.getAttribute('data-year');