fix multi-select icon

packages/theme-default/src/select.css

@@ -115,7 +115,7 @@
           position: absolute;
           right: 10px;
           font-family: 'element-icons';
-          content: "\e920";
+          content: "\E608";
           font-size: 13px;
           -webkit-font-smoothing: antialiased;
           -moz-osx-font-smoothing: grayscale;