template/ucp_main_front.html does not correctly handle active topic with the name "0"

Just a small fix that has been applied to memberlist_view.html and is still missed in ucp_main_front.html

Find:
<td><!-- IF ACTIVE_FORUM --><b><a class="gen" href="

{U_ACTIVE_FORUM}">{ACTIVE_FORUM}</a></b><br /><span class="genmed">[ {ACTIVE_FORUM_POSTS} / {ACTIVE_FORUM_PCT} ]</span><!-- ELSE -><span class="gen"></span><!-- ENDIF --></td>

Replace With:
<td><!-- IF ACTIVE_FORUM != '' --><b><a class="gen" href="{U_ACTIVE_FORUM}

">

{ACTIVE_FORUM}

</a></b><br /><span class="genmed">[

{ACTIVE_FORUM_POSTS}

/

{ACTIVE_FORUM_PCT}

]</span><!-- ELSE -><span class="gen"></span><!-- ENDIF --></td>

Find:
<td><!-- IF ACTIVE_TOPIC --><b><a class="gen" href="

{U_ACTIVE_TOPIC}">{ACTIVE_TOPIC}</a></b><br /><span class="genmed">[ {ACTIVE_TOPIC_POSTS} / {ACTIVE_TOPIC_PCT} ]</span><!-- ELSE -><span class="gen"></span><!-- ENDIF --></td>

Replace With:
<td><!-- IF ACTIVE_TOPIC != '' --><b><a class="gen" href="{U_ACTIVE_TOPIC}

">

{ACTIVE_TOPIC}

</a></b><br /><span class="genmed">[

{ACTIVE_TOPIC_POSTS}

/

{ACTIVE_TOPIC_PCT}

]</span><!-- ELSE -><span class="gen"></span><!-- ENDIF --></td>