MariaDB env file is referred to by a wrong link in install.sh

[steinwinde]

install.sh refers to

https://raw.githubusercontent.com/openMF/mifosx-platform/$branch/$dbtype/fineract-db/docker/$dbtype.env

for MariaDB and PostgreSQL. For PostgreSQL this is the correct path, for MariaDB

https://raw.githubusercontent.com/openMF/mifosx-platform/$branch/$dbtype/.env

seems to be correct.