default.latex: include fontenc only if pdflatex engine is used.

See pandoc #1164.

default.latex

@@ -1,5 +1,4 @@
 \documentclass[$if(fontsize)$$fontsize$,$endif$$if(lang)$$lang$,$endif$$if(papersize)$$papersize$,$endif$$for(classoption)$$classoption$$sep$,$endfor$]{$documentclass$}
-\usepackage[T1]{fontenc}
 \usepackage{lmodern}
 \usepackage{amssymb,amsmath}
 \usepackage{ifxetex,ifluatex}
@@ -7,6 +6,7 @@
 % use upquote if available, for straight quotes in verbatim environments
 \IfFileExists{upquote.sty}{\usepackage{upquote}}{}
 \ifnum 0\ifxetex 1\fi\ifluatex 1\fi=0 % if pdftex
+  \usepackage[T1]{fontenc}
   \usepackage[utf8]{inputenc}
 $if(euro)$
   \usepackage{eurosym}