init: Default database type to JDBC when url is present

If there is no type named in the database section but url is set
force the type to be JDBC. This fixes an upgrade path from 2.1.8 to
2.6 where previously Gerrit assumed JDBC type when url was present
and no type was given.

Bug: issue 1870
Change-Id: I8e30456dd9bb292fc8fc1d9f253413cd676d48ba
1 file changed