updatedb says it wants the values on the right to be quoted

After using this recipe, I got an email saying:
updatedb:/etc/updatedb.conf:1: value in quotes expected after '='
updatedb:/etc/updatedb.conf:2: value in quotes expected after '='
updatedb:/etc/updatedb.conf:3: value in quotes expected after '='
updatedb:/etc/updatedb.conf:4: value in quotes expected after '='

This fix makes those warnings go away.