Fix CVE-2016-10243:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-10243

Patch adapted from upstream commit:

https://www.tug.org/svn/texlive?view=revision&revision=42605

--- trunk/Master/texmf-dist/web2c/texmf.cnf	2016/11/29 23:10:33	42604
+++ trunk/Master/texmf-dist/web2c/texmf.cnf	2016/11/29 23:27:53	42605
@@ -568,7 +568,6 @@ extractbb,\
 gregorio,\
 kpsewhich,\
 makeindex,\
-mpost,\
 repstopdf,\
 
 % we'd like to allow:
cgit logo'/></a></td>
<td class='main'><a href='/'>index</a> : <a href='/guix/'>guix</a></td><td class='form'><form method='get'>
<input type='hidden' name='id' value='c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'>refs</a><a class='active' href='/guix/log/tests/cpio.scm'>log</a><a href='/guix/tree/tests/cpio.scm?id=c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'>tree</a><a href='/guix/commit/tests/cpio.scm?id=c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'>commit</a><a href='/guix/diff/tests/cpio.scm?id=c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/cpio.scm'>
<input type='hidden' name='id' value='c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'>root</a>/<a href='/guix/log/tests?id=c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'>tests</a>/<a href='/guix/log/tests/cpio.scm?id=c100a2d1ce3f16cf28a96e581e85e24b4ae52c68'>cpio.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/cpio.scm?id=c100a2d1ce3f16cf28a96e581e85e24b4ae52c68&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>