tools/scons: update scons to 3.1.1
This version bump includes a bunch of fixes and improvements, which
should fix gpsd build breakage in the package feeds.
Ref: https://github.com/SCons/scons/blob/master/src/CHANGES.txt
Signed-off-by: Russell Senior <[email protected]>
[added missing commit description]
Signed-off-by: Petr Štetiar <[email protected]>