ZCS-12908: set context path on 2FA setup page

[k-kato]

Issue:
In TwoFactorSetup.jsp, a value of contextPath was set at lines 36-39, but it was not set in pageContext attribute. Then ${contextPath} was always empty at line 75.

<script src="${contextPath}/js/TwoFactor_all.js<%=ext%>?v=${version}"></script>

Fix:

• Add pageContext.setAttribute("contextPath", contextPath);