fix #1168 add PageRange option

src/main/assemblies/files/generate-thumbnail

@@ -8,7 +8,7 @@ IMAGE_SIZE=100x100!
 if [ x"$CMD_TYPE" = "xmsoffice" ] ; then
   TARGET_FILE=`echo $URL | sed -e "s#^file:/*#/#g"`
   TMP_FILE=/tmp/thumbnail.$$.pdf
-  unoconv -o $TMP_FILE -f pdf $TARGET_FILE
+  unoconv -e PageRange=1-1 -o $TMP_FILE -f pdf $TARGET_FILE
   convert -thumbnail $IMAGE_SIZE $TMP_FILE $OUTPUT_FILE
   rm $TMP_FILE
 elif [ x"$CMD_TYPE" = "xpdf" ] ; then