instant_preview.lyx: load 'etex' package

The pgf package 3.0.0 update lead to an error being given with
this document. Loading the 'etex' package fixes the problem.
For more information, see:
  https://sourceforge.net/p/pgf/bugs/296/

diff --git a/lib/examples/instant_preview.lyx b/lib/examples/instant_preview.lyx
index 8d53da35e7a2cce8fe777a1da4dfce0260cc6165..2f8b522c853ae433dbd3019d591696233c63ccc1 100644 (file)
--- a/lib/examples/instant_preview.lyx
+++ b/lib/examples/instant_preview.lyx
@@ -4,6 +4,7 @@
 \begin_header
 \textclass article
 \begin_preamble
+\usepackage{etex}
 \usepackage[all, knot]{xy}
 \xyoption{arc} 
 \usepackage{qtree}
@@ -90,7 +91,7 @@ In order to properly typeset the document and have instant preview working,
 \end_layout
 
 \begin_layout LyX-Code
-xy, qtree, tipa, pstricks, pst-plot, rotating, tikz, pgf
+xy, qtree, tipa, pstricks, pst-plot, rotating, tikz, pgf, etex
 \end_layout
 
 \begin_layout Standard