fix of #735

Author: AJIXuMuK

src/controls/taxonomyPicker/TaxonomyPicker.tsx

@@ -15,7 +15,7 @@ import { sortBy, cloneDeep, isEqual } from '@microsoft/sp-lodash-subset';
 import uniqBy from 'lodash/uniqBy';
 import TermParent from './TermParent';
 import FieldErrorMessage from '../errorMessage/ErrorMessage';
-
+import { initializeIcons } from '@uifabric/icons';
 import * as telemetry from '../../common/telemetry';
 
 /**
@@ -27,6 +27,8 @@ export const GROUP_IMG = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQ
 export const TERMSET_IMG = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAACaSURBVDhPrZLRCcAgDERdpZMIjuQA7uWH4CqdxMY0EQtNjKWB0A/77sxF55SKMTalk8a61lqCFqsLiwKac84ZRUUBi7MoYHVmAfjfjzE6vJqZQfie0AcwBQVW8ATi7AR7zGGGNSE6Q2cyLSPIjRswjO7qKhcPDN2hK46w05wZMcEUIG+HrzzcrRsQBIJ5hS8C9fGAPmRwu/9RFxW6L8CM4Ry8AAAAAElFTkSuQmCC'; // /_layouts/15/Images/EMMTermSet.png
 export const TERM_IMG = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAACzSURBVDhPY2AYNKCoqIgTiOcD8X8S8F6wB4Aa1IH4akNDw+mPHz++/E8EuHTp0jmQRSDNCcXFxa/XrVt3gAh9KEpgBvx/9OjRLVI1g9TDDYBp3rlz5//Kysr/IJoYgGEASPPatWsbQDQxAMOAbdu2gZ0FookBcAOePHlyhxgN6GqQY+Hdhg0bDpJqCNgAaDrQAnJuNDY2nvr06dMbYgw6e/bsabgBUEN4yEiJ2wdNViLfIQC3sTh2vtJcswAAAABJRU5ErkJggg==';
 
+initializeIcons();
+
 /**
  * Renders the controls for PropertyFieldTermPicker component
  */