Fix ectaart.lyx reference labels

The labels for the references are now in the format
"author(year)". Without this, the following error is given:

  "Bibliography not compatible with author-year citations"

Thanks to Richard for the fix.

lib/templates/ectaart.lyx

@@ -1,5 +1,5 @@
-#LyX 2.0 created this file. For more info see http://www.lyx.org/
+#LyX 2.1 created this file. For more info see http://www.lyx.org/
-\lyxformat 413
+\lyxformat 474
 \begin_document
 \begin_header
 \textclass ectaart
@@ -25,13 +25,13 @@ theorems-ams
 \font_roman default
 \font_sans default
 \font_typewriter default
+\font_math auto
 \font_default_family default
 \use_non_tex_fonts false
 \font_sc false
 \font_osf false
 \font_sf_scale 100
 \font_tt_scale 100
-
 \graphics default
 \default_output_format default
 \output_sync 0
@@ -42,15 +42,24 @@ theorems-ams
 \use_hyperref false
 \papersize default
 \use_geometry false
-\use_amsmath 1
+\use_package amsmath 1
-\use_esint 1
+\use_package amssymb 1
-\use_mhchem 1
+\use_package cancel 0
-\use_mathdots 1
+\use_package esint 1
-\cite_engine natbib_authoryear
+\use_package mathdots 1
+\use_package mathtools 0
+\use_package mhchem 1
+\use_package stackrel 0
+\use_package stmaryrd 0
+\use_package undertilde 0
+\cite_engine natbib
+\cite_engine_type authoryear
+\biblio_style plainnat
 \use_bibtopic false
 \use_indices false
 \paperorientation portrait
 \suppress_date false
+\justification true
 \use_refstyle 0
 \index Index
 \shortcut idx
@@ -395,7 +404,7 @@ web
 
 \begin_layout Thanks Text
 Short title is used to refer this thanks text.
-\begin_inset Argument
+\begin_inset Argument 1
 status open
 
 \begin_layout Plain Layout
@@ -419,7 +428,7 @@ Add label via Short Title
 
 \begin_layout Thanks Text
 Thanks by the second author.
-\begin_inset Argument
+\begin_inset Argument 1
 status open
 
 \begin_layout Plain Layout
@@ -433,7 +442,7 @@ thk2
 
 \begin_layout Email
 ...@email.address
-\begin_inset Argument
+\begin_inset Argument 1
 status open
 
 \begin_layout Plain Layout
@@ -447,7 +456,7 @@ email
 
 \begin_layout Web Address
 www.my.home.page
-\begin_inset Argument
+\begin_inset Argument 1
 status open
 
 \begin_layout Plain Layout
@@ -504,6 +513,7 @@ Section label must not be inserted in the section line, but put it in the
 \begin_layout Bibliography
 \begin_inset CommandInset bibitem
 LatexCommand bibitem
+label "Smith(1759)"
 key "Smith-1"
 
 \end_inset
@@ -515,6 +525,7 @@ Smith, Adam (1759) The Theory of Moral Sentiments, A.
 \begin_layout Bibliography
 \begin_inset CommandInset bibitem
 LatexCommand bibitem
+label "Smith(1776)"
 key "Smith-2"
 
 \end_inset