Setting the additional include path for host-build of ecpg is no
longer required and started breaking the build (PostgeSQL BUG-14033),
remove it.
Also, pgsql-server no longer requires shadow-su since procd can take
care of starting it running under the appropriate user.
Moving the dependency to pgsql-cli makes sense as the 'su' command is
still needed to boot-strap a new data directory and also commonly used
for other administration tasks. However, in that way the CLI and
shadow-su can be removed during production once pgsql-server has been
setup.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>