Try to make it more likely that a build without any autogen.sh options
succeeds. We didn't even get past the autogen.sh phase on openSUSE 12.3 thanks
to some krb5 stuff needed by the postgresql-sdbc checks.

To compensate, add --enable-postgresql-sdbc to those distro-configs/*.conf
files that didn't already have --disable-postgresql-sdbc.

Change-Id: I967616993875b99d9d5a9fd0721f281bb1161a87