修改预安装脚本，修复安装inf失败的问题

preinstall/install.sh

@@ -6,7 +6,7 @@ touch ${DST}/plug/conflist.inf
 mkdir -p ${DST}/conf/
 touch ${DST}/${CONFILE}
 
-if [[ -z `grep -rn '[business]' ${DST}/plug/conflist.inf` ]];then
+if [[ -z `grep -rn '\[business\]' ${DST}/plug/conflist.inf` ]];then
 	echo '[business]' >> ${DST}/plug/conflist.inf
 fi