Make db connection pool configurable

[gsoyka]

Currently, each worker has a hardcoded limit of 100 database connections in the pool. For some environments, this results in exceeding the number of allowed connections to the database. For PaaS environments and the like, it would be helpful to configure a lower limit.

[ARolek]

@gsoyka great issue. I will add it to the upcoming version. Thanks for the report.

[ARolek]

@gsoyka looks like this is already configurable via the max_connection param for the postgis provider. @jj0hns0n is running some tests bit you should be good to go.

[jj0hns0n]

looks like alex fixed a bug and max_connections now works.

[ARolek]

looks like there was an error parsing the data type (int64 v int) I have a fix coming. I have also adjusted the language to max_connections (plural).