Used https://www.shellcheck.net/ and changed to newer notation.

odoo_install.sh

@@ -93,13 +93,13 @@ sudo npm install -g rtlcss
 if [ $INSTALL_WKHTMLTOPDF = "True" ]; then
   echo -e "\n---- Install wkhtml and place shortcuts on correct place for ODOO 13 ----\n"
   #pick up correct one from x64 & x32 versions:
-  if [ "`getconf LONG_BIT`" == "64" ];then
+  if [ "$(getconf LONG_BIT)" == "64" ]; then
       _url=$WKHTMLTOX_X64
   else
       _url=$WKHTMLTOX_X32
   fi
   sudo wget $_url
-  sudo gdebi --n `basename $_url`
+  sudo gdebi --n "$(basename $_url)"
   sudo ln -s /usr/local/bin/wkhtmltopdf /usr/bin
   sudo ln -s /usr/local/bin/wkhtmltoimage /usr/bin
 else