postgresql: bump to 10.1

postgresql: bump to 10.1

- Add a hash for the license file.

- PostgreSQL 10.0 and above will default to checking for /dev/urandom if an
  SSL library is not found, which will fail when cross compiling.
  Since /dev/urandom is guaranteed to be provided on Linux systems,
  add ac_cv_file__dev_urandom=yes to the configure environment if a SSL library
  is not selected.

Signed-off-by: Adam Duskett <Adamduskett@outlook.com>
[Thomas: minor tweaks to the /dev/urandom comment in the .mk file.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>