Migrated the PropTypes deprecation change for two files that were missed by the codemod.

Author: jmkulwik

apps/src/templates/manageStudents/ManageStudents.jsx

@@ -1,4 +1,5 @@
-import React, {PropTypes} from 'react';
+import React from 'react';
+import PropTypes from 'prop-types';
 import {connect} from 'react-redux';
 import ManageStudentsTable from './ManageStudentsTable';
 import SyncOmniAuthSectionControl from '@cdo/apps/lib/ui/SyncOmniAuthSectionControl';

apps/src/templates/teacherDashboard/SelectSectionDropdown.jsx

@@ -1,4 +1,5 @@
-import React, {PropTypes} from 'react';
+import React from 'react';
+import PropTypes from 'prop-types';
 import {connect} from 'react-redux';
 import i18n from '@cdo/locale';
 import {navigateToHref} from '@cdo/apps/utils';