update_ts.sh: no obsolete translation on push

Author: jef-n

scripts/update_ts.sh

@@ -175,7 +175,7 @@ $QMAKE -project -o qgis_ts.pro -nopwd $PWD/src $PWD/python $PWD/i18n $textcpp
 echo "TR_EXCLUDE = $(qmake -query QT_INSTALL_HEADERS)/*" >>qgis_ts.pro
 
 echo Updating translations
-$LUPDATE -locations absolute -verbose qgis_ts.pro
+$LUPDATE -no-obsolete -locations absolute -verbose qgis_ts.pro
 
 perl -i.bak -ne 'print unless /^\s+<location.*qgs(expression|contexthelp)_texts\.cpp.*$/;' i18n/qgis_*.ts