Avoid changing the variables in the entrypoint

[dmirtillo]

Hello,
I'm currently trying to use your image with a mysql database but this specific function does not allow me to do it

murmur/stable/root/usr/local/bin/entrypoint-functions.sh

Line 48 in 285c617

sed -i '/database=/c\database='"${DATADIR}"'/murmur.sqlite' ${CONFIGDIR}/murmur.ini

Could you avoid overwriting this variable or finding another way to check it beforehand so that actual database names can be used?
Currently this prevent any third-party database to be used.
Best,