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:
